If a package var is used only inside a single file, you can use a lexical without tieing it.

> these values need to be used across the program as a whole.

Hmm, as I said I need to guess to understand your situation.

For instance one of your descriptions fits for constants. I can't see the need to change them in a modperl environment.

And you may be able to go the inverse way, keep those package vars and tie them to a class which adapts to the modperl runtime environment by accessing its values in a lexical hash.

Again plain guess work without you showing an SSCCE.