docs: Categorize some configs as testing and add notes about known time zone issues

[andygrove]

Which issue does this PR close?

Part of #2649

Rationale for this change

Add documentation for recently discovered bug.

What changes are included in this PR?

How are these changes tested?

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 58.46%. Comparing base (f09f8af) to head (9199bc7).
⚠️ Report is 678 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #2740      +/-   ##
============================================
+ Coverage     56.12%   58.46%   +2.34%     
- Complexity      976     1456     +480     
============================================
  Files           119      159      +40     
  Lines         11743    13893    +2150     
  Branches       2251     2375     +124     
============================================
+ Hits           6591     8123    +1532     
- Misses         4012     4570     +558     
- Partials       1140     1200      +60     

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[comphead]

Thanks @andygrove