I like the trick but, unfortunately, the evil of my users far surpasses it. Its not uncommon to see code such as:

  my $value= ${ uc join "_", @$reg_spec{ qw( device reg field ) } };
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You really don't want to see some of the more nasty code. Honest. Especially not the 70000 line regex (its one saving grace is the /x modifier). And perhaps not the script that parses another script's --verbose output. Or perhaps ...