I took BrowserUk's example and added Time::Out. It returns a slightly different result.

Not slightly different. Completely different. And wrong.

Your code isn't doing anything like what you think it is doing. Actually, it isn't doing anything at all.

This:

            eval {
                 sub test {
                     timeout 10, @_ => sub {
                         print "$_[0]";
                     };
                 }
             };
[download]

evals the sub test into existence, but then it never actually calls that sub.

• The eval is pointless, because the code inside it can never fail.
• The code inside the sub is useless, because it is never called.
• You render the parameter passed to the thread useless, by never using it.

  Which in turn renders the purpose of the demonstration -- showing that the timeout is effective -- useless.

• You've used a module which itself is useless, because it uses almost 100 lines of code to do what you can standard Perl in 2 lines.

  And with no value add.

• And you compounded that by using it incorrectly, rendering it even less useful.
• Your code ends up being the exact equivalent of:

  #! perl -slw
  use strict
  
  do {
      my $tid      = int( rand ); #'threads'->tid;
      my $worktime = shift @_;
      print "Thread $tid started with a worktime of $worktime";
      print "Thread $tid ended ", $@ ? " with error: $@" : "normally";
  } for  1 .. 4;
  [download]

In other words, your post is ... I'll let you guess the word I'm thinking of here. (Sorry, but it's true!)

FWIW: I applaud you for having a go :)