I know you should have all ingredients room temp for baking, but what about making meringue buttercreams?
Eggs do whip higher at room temp. But there's no need to leave them sitting out. Just warm them in the shell in a bowl of warm water for 5 minutes. Butter also needs to be room temp but still firm.
I just made a batch a couple if days ago. I still don't like the taste of the stuff.