On the old briliantgameologists board, I recall a thread where there was mention of a specific 3rd party metamagic feat. IIRC, it was a +1 to the level, and allowed the caster to remove a descriptor for a spell they can cast. For example, it could remove [mind affecting] from an enchantment spell(which is awesome).
I saved the information somewhere, but I seemingly can no longer find it. Does anyone have the name and/or sourcebook?