I'd have expected Perl 6 to have less boilerplate than Perl 5 for parallel processing. It's just that the advantage is smaller when you know about MCE than when you try to figure all of that out with Perl 5 core. So this is a Perl 6 benefit in the same order of magnitude as with objects, where I need to use Moose; in Perl 5 to get the object magic.
Two minor nitpickings:
$call.status == 204 ?? $results<OK>++ !! $results<NOT_OK>++; seems somewhat Perl5ish. Shouldn't that read like that:
$call.status == 204 ?? %results<OK>++ !! %results<NOT_OK>++;
- You write: "I've used the ASCII equivalent of the atomic increment operator, since PerlMonks does not display the unicode equivalent "++⚛️" inside code blocks properly.". I'm glad you did, because this is another example why I don't like these unicode operators: I have no idea how to enter it into my keyboard easily, and my preferred font in my preferred editor doesn't have a glyph for it. There also seems to be another, quite similar symbol: "++⚛" which has an almost identical glyph in the textarea field into which I'm typing right now. I am pretty sure that I'll never use these symbols, and I hope I'll never need to maintain code which contains them.