I have trouble to understand the concept of a lexically scoped base class, and that's what %^H is normally used for.

But I think instead of hacking Moose, you should try to hide all magic inside an MagicBase::import() which calls extends in the callers package for you and just do use MagicBase qw/-feature/ .

Like that you avoid boilerplating hacks and you can put all magical documentation inside your module.