Uh...Modular Abilities as an Item of Power is (or can be) almost exactly that.
That's actually a really neat, and elegant, idea for a James Potter...or Harry Bond...
The only issue I could see the OP having with that is owning an Item of Power invalidates the Pure Mortal thing...at least "by the book". Granted, having that kind of power at the character's fingertips maybe should invalidate that, or at least invalidate the bonus +2 refresh. Personally, I could live with calling myself a Pure Mortal and skipping the bonus +2, but still keeping the "title", so to speak.