diff --git a/src/FSharp.Control.TaskSeq.SmokeTests/FSharp.Control.TaskSeq.SmokeTests.fsproj b/src/FSharp.Control.TaskSeq.SmokeTests/FSharp.Control.TaskSeq.SmokeTests.fsproj
index 75c962ec..a8fbec80 100644
--- a/src/FSharp.Control.TaskSeq.SmokeTests/FSharp.Control.TaskSeq.SmokeTests.fsproj
+++ b/src/FSharp.Control.TaskSeq.SmokeTests/FSharp.Control.TaskSeq.SmokeTests.fsproj
@@ -9,13 +9,16 @@
   </ItemGroup>
 
   <ItemGroup>
+    <Compile Include="TestUtils.fs" />
     <Compile Include="SmokeTests.fs" />
+    <Compile Include="TaskSeq.PocTests.fs" />
   </ItemGroup>
 
   <ItemGroup>
     <!-- our smoketests use the highest RTM (non-alpha) FSharp.Core, contrary to the base test project, which uses the lowest possible denominator -->
     <PackageReference Update="FSharp.Core" Version="7.0.401" />
     <PackageReference Include="FSharp.Control.TaskSeq" Version="0.4.0-alpha.1" />
+    <PackageReference Include="FsToolkit.ErrorHandling.TaskResult" Version="4.10.0" />
     <PackageReference Include="FsUnit.xUnit" Version="5.5.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.7.2" />
     <PackageReference Include="xunit" Version="2.5.3" />
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.PocTests.fs b/src/FSharp.Control.TaskSeq.SmokeTests/TaskSeq.PocTests.fs
similarity index 100%
rename from src/FSharp.Control.TaskSeq.Test/TaskSeq.PocTests.fs
rename to src/FSharp.Control.TaskSeq.SmokeTests/TaskSeq.PocTests.fs
diff --git a/src/FSharp.Control.TaskSeq.SmokeTests/TestUtils.fs b/src/FSharp.Control.TaskSeq.SmokeTests/TestUtils.fs
new file mode 100644
index 00000000..deb01c98
--- /dev/null
+++ b/src/FSharp.Control.TaskSeq.SmokeTests/TestUtils.fs
@@ -0,0 +1,131 @@
+namespace TaskSeq.Tests
+
+open System
+open System.Threading
+open System.Threading.Tasks
+open System.Diagnostics
+open System.Collections.Generic
+
+open Xunit
+open Xunit.Abstractions
+open FsUnit.Xunit
+
+open FSharp.Control
+
+/// Milliseconds
+[<Measure>]
+type ms
+
+/// Microseconds
+[<Measure>]
+type µs
+
+/// Helpers for short waits, as Task.Delay has about 15ms precision.
+/// Inspired by IoT code: https://github.com/dotnet/iot/pull/235/files
+module DelayHelper =
+
+    let private rnd = Random()
+
+    /// <summary>
+    /// Delay for at least the specified <paramref name="microseconds"/>.
+    /// </summary>
+    /// <param name="microseconds">The number of microseconds to delay.</param>
+    /// <param name="allowThreadYield">
+    /// True to allow yielding the thread. If this is set to false, on single-proc systems
+    /// this will prevent all other code from running.
+    /// </param>
+    let spinWaitDelay (microseconds: int64<µs>) (allowThreadYield: bool) =
+        let start = Stopwatch.GetTimestamp()
+        let minimumTicks = int64 microseconds * Stopwatch.Frequency / 1_000_000L
+
+        // FIXME: though this is part of official IoT code, the `allowThreadYield` version is extremely slow
+        // slower than would be expected from a simple SpinOnce. Though this may be caused by scenarios with
+        // many tasks at once. Have to investigate. See perf smoke tests.
+        if allowThreadYield then
+            let spinWait = SpinWait()
+
+            while Stopwatch.GetTimestamp() - start < minimumTicks do
+                spinWait.SpinOnce(1)
+
+        else
+            while Stopwatch.GetTimestamp() - start < minimumTicks do
+                Thread.SpinWait(1)
+
+    let delayTask (µsecMin: int64<µs>) (µsecMax: int64<µs>) f = task {
+        let rnd () = rnd.NextInt64(int64 µsecMin, int64 µsecMax) * 1L<µs>
+
+        // ensure unequal running lengths and points-in-time for assigning the variable
+        // DO NOT use Thead.Sleep(), it's blocking!
+        // WARNING: Task.Delay only has a 15ms timer resolution!!!
+
+        // TODO: check this! The following comment may not be correct
+        // this creates a resume state, which seems more efficient than SpinWait.SpinOnce, see DelayHelper.
+        let! _ = Task.Delay 0
+        let delay = rnd ()
+
+        // typical minimum accuracy of Task.Delay is 15.6ms
+        // for delay-cases shorter than that, we use SpinWait
+        if delay < 15_000L<µs> then
+            do spinWaitDelay (rnd ()) false
+        else
+            do! Task.Delay(int <| float delay / 1_000.0)
+
+        return f ()
+    }
+
+/// <summary>
+/// Creates dummy backgroundTasks with a randomized delay and a mutable state,
+/// to ensure we properly test whether processing is done ordered or not.
+/// Default for <paramref name="µsecMin" /> and <paramref name="µsecMax" />
+/// are 10,000µs and 30,000µs respectively (or 10ms and 30ms).
+/// </summary>
+type DummyTaskFactory(µsecMin: int64<µs>, µsecMax: int64<µs>) =
+    let mutable x = 0
+
+    /// <summary>
+    /// Creates dummy tasks with a randomized delay and a mutable state,
+    /// to ensure we properly test whether processing is done ordered or not.
+    /// Uses the defaults for <paramref name="µsecMin" /> and <paramref name="µsecMax" />
+    /// with 10,000µs and 30,000µs respectively (or 10ms and 30ms).
+    /// </summary>
+    new() = new DummyTaskFactory(10_000L<µs>, 30_000L<µs>)
+
+
+    /// Bunch of delayed tasks that randomly have a yielding delay of 10-30ms, therefore having overlapping execution times.
+    member _.CreateDelayedTasks_SideEffect total = [
+        for i in 0 .. total - 1 do
+            fun () -> DelayHelper.delayTask µsecMin µsecMax (fun _ -> Interlocked.Increment &x)
+    ]
+
+/// Just some dummy task generators, copied over from the base test project, with artificial delays,
+/// mostly to ensure sequential async operation of side effects.
+module Gen =
+    /// Joins two tasks using merely BCL methods. This approach is what you can use to
+    /// properly, sequentially execute a chain of tasks in a non-blocking, non-overlapping way.
+    let joinWithContinuation tasks =
+        let simple (t: unit -> Task<_>) (source: unit -> Task<_>) : unit -> Task<_> =
+            fun () ->
+                source()
+                    .ContinueWith((fun (_: Task) -> t ()), TaskContinuationOptions.OnlyOnRanToCompletion)
+                    .Unwrap()
+                :?> Task<_>
+
+        let rec combine acc (tasks: (unit -> Task<_>) list) =
+            match tasks with
+            | [] -> acc
+            | t :: tail -> combine (simple t acc) tail
+
+        match tasks with
+        | first :: rest -> combine first rest
+        | [] -> failwith "oh oh, no tasks given!"
+
+    let joinIdentityHotStarted tasks () = task { return tasks |> List.map (fun t -> t ()) }
+
+    let joinIdentityDelayed tasks () = task { return tasks }
+
+    let createAndJoinMultipleTasks total joiner : Task<_> =
+        // the actual creation of tasks
+        let tasks = DummyTaskFactory().CreateDelayedTasks_SideEffect total
+        let combinedTask = joiner tasks
+        // start the combined tasks
+        combinedTask ()
diff --git a/src/FSharp.Control.TaskSeq.Test/FSharp.Control.TaskSeq.Test.fsproj b/src/FSharp.Control.TaskSeq.Test/FSharp.Control.TaskSeq.Test.fsproj
index b6d84d11..43ac2020 100644
--- a/src/FSharp.Control.TaskSeq.Test/FSharp.Control.TaskSeq.Test.fsproj
+++ b/src/FSharp.Control.TaskSeq.Test/FSharp.Control.TaskSeq.Test.fsproj
@@ -42,7 +42,6 @@
     <Compile Include="TaskSeq.Tests.CE.fs" />
     <Compile Include="TaskSeq.StateTransitionBug.Tests.CE.fs" />
     <Compile Include="TaskSeq.StateTransitionBug-delayed.Tests.CE.fs" />
-    <Compile Include="TaskSeq.PocTests.fs" />
     <Compile Include="TaskSeq.Realworld.fs" />
     <Compile Include="TaskSeq.AsyncExtensions.Tests.fs" />
     <Compile Include="TaskSeq.TaskExtensions.Tests.fs" />
@@ -52,10 +51,8 @@
   </ItemGroup>
 
   <ItemGroup>
-    <!-- align test project with minimal required version for TaskSeq -->
-    <!-- we use 6.0.3 here and not 6.0.2 because TaskResult lib requires it-->
-    <PackageReference Update="FSharp.Core" Version="6.0.3" />
-    <PackageReference Include="FsToolkit.ErrorHandling.TaskResult" Version="3.2.0" />
+    <!-- align test project with minimal required version for TaskSeq, which is 6.0.1 at the moment -->
+    <PackageReference Update="FSharp.Core" Version="6.0.1" />
     <PackageReference Include="FsUnit.xUnit" Version="5.5.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.7.2" />
     <PackageReference Include="xunit" Version="2.5.3" />
diff --git a/src/FSharp.Control.TaskSeq.Test/Nunit.Extensions.fs b/src/FSharp.Control.TaskSeq.Test/Nunit.Extensions.fs
index 834afe02..eb67fecf 100644
--- a/src/FSharp.Control.TaskSeq.Test/Nunit.Extensions.fs
+++ b/src/FSharp.Control.TaskSeq.Test/Nunit.Extensions.fs
@@ -2,11 +2,11 @@ namespace TaskSeq.Tests
 
 open System
 open System.Threading.Tasks
+
 open FsUnit
 open NHamcrest.Core
 open Microsoft.FSharp.Reflection
 
-open FsToolkit.ErrorHandling
 open Xunit
 open Xunit.Sdk
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Append.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Append.Tests.fs
index 8eb39454..32010192 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Append.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Append.Tests.fs
@@ -1,13 +1,9 @@
 module TaskSeq.Tests.Append
 
-open System
-
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
-open System.Collections.Generic
 
 //
 // TaskSeq.append
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.AsyncExtensions.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.AsyncExtensions.Tests.fs
index 1f0b9efd..62d58368 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.AsyncExtensions.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.AsyncExtensions.Tests.fs
@@ -1,6 +1,5 @@
 module TaskSeq.Tests.AsyncExtensions
 
-open System
 open Xunit
 open FsUnit.Xunit
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Cast.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Cast.Tests.fs
index f63e9e9d..b8a423fe 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Cast.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Cast.Tests.fs
@@ -4,7 +4,6 @@ open System
 
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Choose.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Choose.Tests.fs
index b5376d5b..6258a760 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Choose.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Choose.Tests.fs
@@ -1,11 +1,9 @@
 module TaskSeq.Tests.Choose
 
 open System
-open System.Threading.Tasks
 
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Collect.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Collect.Tests.fs
index 6b71e075..48b1ec41 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Collect.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Collect.Tests.fs
@@ -2,7 +2,6 @@ module TaskSeq.Tests.Collect
 
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Concat.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Concat.Tests.fs
index 6b9f3d68..352aa4c7 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Concat.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Concat.Tests.fs
@@ -1,13 +1,11 @@
 module TaskSeq.Tests.Concat
 
-open System
+open System.Collections.Generic
 
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
-open System.Collections.Generic
 
 //
 // TaskSeq.concat
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Contains.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Contains.Tests.fs
index 3d84956f..9b326a70 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Contains.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Contains.Tests.fs
@@ -2,7 +2,6 @@ module TaskSeq.Tests.Contains
 
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Delay.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Delay.Tests.fs
index a13c9111..c437bebc 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Delay.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Delay.Tests.fs
@@ -1,13 +1,9 @@
 module TaskSeq.Tests.Delay
 
-open System
-
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
-open System.Collections.Generic
 
 //
 // TaskSeq.delay
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Do.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Do.Tests.fs
index 09c3c7b3..1f8badae 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Do.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Do.Tests.fs
@@ -1,7 +1,7 @@
 module TaskSeq.Tests.Do
 
-open System
 open System.Threading.Tasks
+
 open FsUnit
 open Xunit
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Empty.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Empty.Tests.fs
index 0e73b90f..219b21be 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Empty.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Empty.Tests.fs
@@ -3,7 +3,6 @@ module TaskSeq.Tests.Empty
 open System.Threading.Tasks
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
@@ -42,7 +41,7 @@ let ``TaskSeq-empty of unit in a taskSeq context`` () = task {
 [<Fact>]
 let ``TaskSeq-empty of more complex type in a taskSeq context`` () = task {
     let! sq =
-        taskSeq { yield! TaskSeq.empty<Result<Task<string>, int>> }
+        taskSeq { yield! TaskSeq.empty<Result<Task<string>, int>> } // not a TaskResult, but a ResultTask lol
         |> TaskSeq.toArrayAsync
 
     Array.isEmpty sq |> should be True
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.ExactlyOne.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.ExactlyOne.Tests.fs
index 0438086c..2a2a01d7 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.ExactlyOne.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.ExactlyOne.Tests.fs
@@ -1,9 +1,9 @@
 module TaskSeq.Tests.ExactlyOne
 
 open System
+
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Except.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Except.Tests.fs
index b0cda375..db49b2c0 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Except.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Except.Tests.fs
@@ -1,9 +1,7 @@
 module TaskSeq.Tests.Except
 
-open System
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Exists.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Exists.Tests.fs
index 1fe3541c..04a652f5 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Exists.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Exists.Tests.fs
@@ -2,7 +2,6 @@ module TaskSeq.Tests.Exists
 
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Filter.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Filter.Tests.fs
index 0dfe5963..fb67ad9f 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Filter.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Filter.Tests.fs
@@ -1,9 +1,9 @@
 module TaskSeq.Tests.Filter
 
 open System
+
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Find.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Find.Tests.fs
index 61a6e02e..9ad3ede8 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Find.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Find.Tests.fs
@@ -1,11 +1,11 @@
 module TaskSeq.Tests.Find
 
+open System.Collections.Generic
+
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
-open System.Collections.Generic
 
 //
 // TaskSeq.find
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.FindIndex.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.FindIndex.Tests.fs
index f65302b0..96a9e04c 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.FindIndex.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.FindIndex.Tests.fs
@@ -1,11 +1,11 @@
 module TaskSeq.Tests.FindIndex
 
+open System.Collections.Generic
+
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
-open System.Collections.Generic
 
 //
 // TaskSeq.findIndex
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Fold.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Fold.Tests.fs
index 1b0791b4..aa91c046 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Fold.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Fold.Tests.fs
@@ -1,9 +1,9 @@
 module TaskSeq.Tests.Fold
 
 open System.Text
+
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Head.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Head.Tests.fs
index a1dc1993..af4cd8fc 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Head.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Head.Tests.fs
@@ -1,9 +1,9 @@
 module TaskSeq.Tests.Head
 
 open System
+
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Indexed.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Indexed.Tests.fs
index 4ebab7b6..0d69753d 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Indexed.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Indexed.Tests.fs
@@ -2,7 +2,6 @@ module TaskSeq.Tests.Indexed
 
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Init.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Init.Tests.fs
index 0e65e47a..2c1a445c 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Init.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Init.Tests.fs
@@ -4,7 +4,6 @@ open System
 
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.IsEmpty.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.IsEmpty.fs
index 2d9de691..09925828 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.IsEmpty.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.IsEmpty.fs
@@ -1,9 +1,7 @@
 module TaskSeq.Tests.IsEmpty
 
-open System.Threading.Tasks
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Item.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Item.Tests.fs
index 5e922f90..d2fb2708 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Item.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Item.Tests.fs
@@ -1,9 +1,9 @@
 module TaskSeq.Tests.Item
 
 open System
+
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Last.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Last.Tests.fs
index 82febc02..c74e8136 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Last.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Last.Tests.fs
@@ -1,9 +1,9 @@
 module TaskSeq.Tests.Last
 
 open System
+
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Length.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Length.Tests.fs
index 900aa539..ac8c3882 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Length.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Length.Tests.fs
@@ -1,9 +1,7 @@
 module TaskSeq.Tests.Length
 
-open System
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Let.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Let.Tests.fs
index 5ebd14bd..e7c37844 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Let.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Let.Tests.fs
@@ -2,6 +2,7 @@ module TaskSeq.Tests.Let
 
 open System
 open System.Threading.Tasks
+
 open FsUnit
 open Xunit
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Map.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Map.Tests.fs
index 1f77c1f5..e266b3c9 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Map.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Map.Tests.fs
@@ -2,7 +2,6 @@ module TaskSeq.Tests.Map
 
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.OfXXX.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.OfXXX.Tests.fs
index c32ad822..11354a3d 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.OfXXX.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.OfXXX.Tests.fs
@@ -2,7 +2,6 @@ module TaskSeq.Tests.``Conversion-From``
 
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Pick.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Pick.Tests.fs
index 9fd7ac5c..e03c236b 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Pick.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Pick.Tests.fs
@@ -1,10 +1,9 @@
 module TaskSeq.Tests.Pick
 
-open System
 open System.Collections.Generic
+
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Realworld.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Realworld.fs
index 7ccf043f..f7c8594f 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Realworld.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Realworld.fs
@@ -2,14 +2,13 @@ namespace TaskSeq.Tests
 
 open System
 open System.IO
+open System.Threading.Tasks
+open System.Collections.Generic
+
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
-open System.Threading.Tasks
-open System.Diagnostics
-open System.Collections.Generic
 open Xunit.Abstractions
 
 /// Just a naive, simple in-memory reader that acts as an IAsyncEnumerable to use with tests
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Singleton.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Singleton.Tests.fs
index aec6fbbf..71a07e9e 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Singleton.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Singleton.Tests.fs
@@ -2,7 +2,6 @@ module TaskSeq.Tests.Singleton
 
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.StateTransitionBug-delayed.Tests.CE.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.StateTransitionBug-delayed.Tests.CE.fs
index e5575da1..8eb699bf 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.StateTransitionBug-delayed.Tests.CE.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.StateTransitionBug-delayed.Tests.CE.fs
@@ -1,13 +1,9 @@
 module TaskSeq.Tests.``Bug #42 -- asynchronous`` // see PR #42
 
 open System
-open System.Threading.Tasks
-open System.Diagnostics
-open System.Collections.Generic
 
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.StateTransitionBug.Tests.CE.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.StateTransitionBug.Tests.CE.fs
index 1a421dbc..0861911e 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.StateTransitionBug.Tests.CE.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.StateTransitionBug.Tests.CE.fs
@@ -2,12 +2,10 @@ module TaskSeq.Tests.``Bug #42 -- synchronous`` // see PR #42
 
 open System
 open System.Threading.Tasks
-open System.Diagnostics
 open System.Collections.Generic
 
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Tail.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Tail.Tests.fs
index 9ba6a8af..38868127 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Tail.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Tail.Tests.fs
@@ -1,9 +1,9 @@
 module TaskSeq.Tests.Tail
 
 open System
+
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.TakeWhile.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.TakeWhile.Tests.fs
index 7edc650c..30c15924 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.TakeWhile.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.TakeWhile.Tests.fs
@@ -1,9 +1,9 @@
 module TaskSeq.Tests.TakeWhile
 
 open System
+
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.TaskExtensions.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.TaskExtensions.Tests.fs
index 5d5316a4..0121663f 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.TaskExtensions.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.TaskExtensions.Tests.fs
@@ -1,6 +1,5 @@
 module TaskSeq.Tests.TaskExtensions
 
-open System
 open Xunit
 open FsUnit.Xunit
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Tests.CE.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Tests.CE.fs
index cd7be9b1..d4fee3b0 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Tests.CE.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Tests.CE.fs
@@ -4,7 +4,6 @@ open System
 
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.ToXXX.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.ToXXX.Tests.fs
index fbb5635b..082fe98d 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.ToXXX.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.ToXXX.Tests.fs
@@ -1,11 +1,11 @@
 module TaskSeq.Tests.``Conversion-To``
 
+open System.Collections.Generic
+
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
-open System.Collections.Generic
 
 ////////////////////////////////////////////////////////////////////////////
 ///                                                                      ///
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Using.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Using.Tests.fs
index bf53f14d..557381e0 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Using.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Using.Tests.fs
@@ -2,6 +2,7 @@ module TaskSeq.Tests.Using
 
 open System
 open System.Threading.Tasks
+
 open FSharp.Control
 open FsUnit
 open Xunit
diff --git a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Zip.Tests.fs b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Zip.Tests.fs
index 2ead6106..6ef461fb 100644
--- a/src/FSharp.Control.TaskSeq.Test/TaskSeq.Zip.Tests.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TaskSeq.Zip.Tests.fs
@@ -1,9 +1,7 @@
 module TaskSeq.Tests.Zip
 
-open System
 open Xunit
 open FsUnit.Xunit
-open FsToolkit.ErrorHandling
 
 open FSharp.Control
 
diff --git a/src/FSharp.Control.TaskSeq.Test/TestUtils.fs b/src/FSharp.Control.TaskSeq.Test/TestUtils.fs
index e97f3658..59c8dbb9 100644
--- a/src/FSharp.Control.TaskSeq.Test/TestUtils.fs
+++ b/src/FSharp.Control.TaskSeq.Test/TestUtils.fs
@@ -4,17 +4,13 @@ open System
 open System.Threading
 open System.Threading.Tasks
 open System.Diagnostics
-
-open FsToolkit.ErrorHandling
-
-open FSharp.Control
 open System.Collections.Generic
-open FsUnit.Xunit
+
 open Xunit
 open Xunit.Abstractions
-open System.Runtime.Serialization
-open System.Reflection
-open Microsoft.FSharp.Reflection
+open FsUnit.Xunit
+
+open FSharp.Control
 
 /// Milliseconds
 [<Measure>]
@@ -28,6 +24,8 @@ type µs
 /// Inspired by IoT code: https://github.com/dotnet/iot/pull/235/files
 module DelayHelper =
 
+    let private rnd = Random()
+
     /// <summary>
     /// Delay for at least the specified <paramref name="microseconds"/>.
     /// </summary>
@@ -54,7 +52,6 @@ module DelayHelper =
                 Thread.SpinWait(1)
 
     let delayTask (µsecMin: int64<µs>) (µsecMax: int64<µs>) f = task {
-        let rnd = Random()
         let rnd () = rnd.NextInt64(int64 µsecMin, int64 µsecMax) * 1L<µs>
 
         // ensure unequal running lengths and points-in-time for assigning the variable
@@ -84,8 +81,6 @@ module DelayHelper =
 /// </summary>
 type DummyTaskFactory(µsecMin: int64<µs>, µsecMax: int64<µs>) =
     let mutable x = 0
-    let rnd = Random()
-    let rnd () = rnd.NextInt64(int64 µsecMin, int64 µsecMax) * 1L<µs>
 
     let runTaskDelayed () = backgroundTask { return! DelayHelper.delayTask µsecMin µsecMax (fun _ -> Interlocked.Increment &x) }