Minor regex nit:

Rather than checking the entire key for having uppercase letters and then negating the rest, you could check for the presence of any non-uppercase letter:

delete $runset{$_} for ( grep { /[^A-Z]/ } keys %runset );

Of course, this will also allow the null hash key as well, so you might want to extend the grep to grep { $_ && /[^A-Z]/ }, and by that point, you may have sacrificed the savings on the regex.

- Richie