Personally, I'd suggest not doing this. As soon as you start tracing/logging each thread to a different console, you loose sight of any ordering. Better to trace to a single console, serialise the access to that console and prefix your messages with the thread id.

my $semErr :shared;
sub twarn {
    lock $semErr;
    my $tid = thread->tid;
    warn sprintf("[%3d]", $tid), @_; 
}

...

twarn "Something happened\n";
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You can then filter stderr to concentrate on individual threads.