Now I understand your objection (I was just confused with both after(timer) events from your example and your description).

Indeed it is possible..., but not what you provided as block "to remove",
this one would be enough to remove:

2752-2756)]

Of course with move of `Tcl_MutexUnlock(&threadMutex);` (line 2747) 2 lines down, into block `if ((flags & THREAD_SEND_WAIT))`.

I'll take a look later as regards the test-cases and some other dependencies and behavior etc.