So you have initialized a JOS instance, now you want to change the jos member's value.. now you are doomed coz idk why but for exmaple : startVisible attribute inside of JOS is jos_default_startVisiblr...
& On re initing the JOS instance the, the options that are not given/mentioned gets carried over from previous JOS instance/settings.
re init should reset the settings for options that are not passed to it explicitly .