If incompatibilities even happen between the same Perl version, then most likely from uninstalled modules or their differing versions. Both dists come with a bunch of preinstalled CPAN modules, so you might need to adjust.

Different Perl versions might confront you with deprecations, such that you'll need to fix the code. But Perl tends to be extremely backwards compatible.

You just need to test it.

edit

Probably trying different Perl versions in between to facilitate nailing down the deprecations.