Whenever I install Perl, it always installs to /usr/local/bin/perl5.x.x-blahblah, where blahblah is something like 64, thread, etc. I then symlink /usr/local/bin/perl to whichever I feel is the appropriate default. But, various apps can choose to pick a different Perl, should they choose. (I do the same thing with every Unix app, actually.)

Then, test-suites are good things.

(Plus, you do have an identical dev for your prod where you can test these changes, right?)