So will Milo's xp return over time in much the same way that Potterverse wizards regain their happy memories after being away from a Dementor and getting some chocolate or are you trying to nerf him before he gets back to Hogwarts? I can see arguements fo

It’s not about nerfing him so much as it is about thinking “what’s the logical conclusion of X happening?”

In my opinion, draining happy memories pretty thoroughly equals draining XP from an adventurer.

I think giving him chocolate would cheer him up, but it wouldn’t bring his XP back. He has to do some combat and/or roleplaying and/or questing to do that.