I like making Quick Preparation a part of a wizards standard preparation, but I was thinking of a limitation that will not generally impact people, but it could every once in a while, and would certainly make sense.
Quick Preparation only allows you to swap out a spell slot with a new spell slot if you are using Your spellbook and the spell was written by you. If someone recovers and takes possession of another spellcaster's spellbook. They can't use quick preparation to use that tome to quickly replace their slot, even if that spell is one that they already know (or maybe even have studied from that tome before).
The idea being, to quickly replace the spell without losing any magical energies, they need to have it written in their own personal style.
Perhaps an additional feat might allow someone to do a quick preparation, with a spell they know, but from any source, potentially including scrolls or other casters spellbooks. (or maybe even from a currently existing memorized spell, allowing if they have one spell memorized, replace another slot with another slot of the same spell)