You've stated all the pieces of what you need to do - just not matched them up.

You consider recompiling perl, but for the wrong reason. When you run ./Configure before building perl, you get the opportunity to add vendor library locations to @INC. Rebuilding perl with the actual library path will solve your path problem.

I try to avoid suid scripts if I can. Try to find a way of doing what you can do with a special group and group permissions on the objects you need to modify.

If you still need suid, that's all the more reason to run in taint mode. Don't choose a solution that steps around that.

I would be nervous of a product whose installation permitted a non-default location without adjusting its internals to match.