You're right about strict, because it's encapsulating non-obvious behavior, but I don't use lib, base, or File::Slurp. (The pragmas are less defendable on the same idea, but File::Slurp has crossed a line of encapsulation.)

If you think it's necessary to write a module to encapsulate an assignment to %INC, go ahead. I think it's of dubious value -- of the times I needed to fake a module, I had to do several other things at the same time.

My instinct is to say that the type of people who would need this module already know how to do what it does and are likely to do it themselves.