I like being in robes and books and stuff i can get on other events that are not PVP, even BB after FM ends tends to give 1 customization + stay a bit more hours up or days. So overall no need. Thank you, i won't log in on those days!I tried only logging in to the dormitory at first, to see if that prevented you from getting sorted into a FM group, but I don't think it does. Not logging in at all is the only way to prevent getting into a group.
I don't even care about the FM rewards anymore after I found out you can use cheat engine on pc to temporarily unlock and equip any cosmetics in the game, even if you don't own them.