Do you mean having a persona when hanging out with a confidant? Than yeah, level doesn't matter.
Exactly that. I knew it didn't in the previous games, but wanted to make sure. Didn't want to waste a ton of money withdrawing from the compendium.
Also, do mementos quest unlock no matter what or do I need to finish the last quest first? I currently have the one that had an anime episode, but I want to let them stack up before going in so I can do them all in one go. Haven't had any new ones in a while though.