He doesn't have to leave clan if his clan is not signing up for war if they are signing up then yes you have to be out of clan before roster lock tomorrow
I prefer the opt out spell just because if you opt out and want to be in, just do something else while waiting, i.e. Quests. The opt in spell on the other hand, if you opt in and have estoc edge, you have to leave the clan and lose it if you can't participate
Dude Devs should let me xtal as much as I want because it's me vs RCA. If xtal hundreds of times till they're out then win rofl