A trainer wont be made to do anything of the sort EXP, Credits, unlock everything. Since this is the games system to make it F2P but the access to all the guns (what you need EXP and Credits for) is purchasable. Making a trainer would therefor hurt the sales of the Access pack. MAF Doesnt do that. same as you cant get trainers from him that give you "purchase only" currency for games. Those stats are probably stored server side anyway and if not modifying them is Illegal and a violation of the License agreement.