try to set value at "4", no need to be freezed and set value before join lobby then if you dont use healt or ammo you can close CE. Usualy 1 prestige at game (20 ranks min) but depends on the number of kills you make. Before there's another XP multipler, used for multiplayer and squad mode. Open memory viewer, to see the code or see wath hapens when you launch Xp lobby maker (noticed yesterday trying to change the game type directly in lobby after force host)