You're thinking of 'Force Boon,' which wouldn't work, as you say. There are, IIRC, a *very* limited number of circumstances where you might be able to spend three FP this way, so you'd be getting a "free" FP, but those are vanishingly rare - if they exist at all; I might be thinking of the 'Master of the Force' special ability from the minis game.
I was talking about 'Force Training,' however, which adds (1 + Wis mod) Force powers. With a Wis of at least 12, you could grab a standard action FP and a swift action FP and use both in the round, rather than using a FP to refresh one of the Force powers you already know. Hence, using a FP to replenish a known Force power would be almost entirely useless. I suppose if you wanted to use it again, but not necessarily that round - but then, why not wait and spend the FP *later*?