I hope when Larian fixes this problem, they also allow the host to create custom characters for the whole party and either advertise them in multiplayer or use them all in singleplayer. If someone joins multiplayer, they can either use the character provided or respec and if they quit, the host can either, respec back to the originally advertised character, play the respecced character, or leave the character in camp. That should prevent anyone from "messing up" a multiplayer game.