[Chaos]

We've had this sort of discussion a LONG time ago, and the bottom line was this:

HP comes and goes easily.
FP is a valuable asset, and requires careful management.

You already have plenty of methods to restore and conserve FP to begin with. I don't see why we need to add an easily-abusable mechanic to that list. (not to mention what an FP-restoring march would invalidate)