My goal is solely to improve the execution time of my very large codebase which runs as CGI

Seems futile , but here you go:
PAR::Filter::Squish
PAR::Filter::PodStrip
PAR::Filter::Obfuscate - This filter uses B::Deobfuscate (available separately from CPAN) to turn the script into comment-free, architecture-independent Perl code with mangled variable names.
Perl::Squish - Reduce Perl code to a few characters as possible