In my current PT, I finished Act 1 and decided to stay at LVL 6 during act 2 to see how far I could get. But it turns out to be psychologically annoying because you can't see the XP amount anymore as it is hidden by the "level up" flag. So to add some relieve I'm just leveling up Wyll. I don't want him in my party as a combatant anyway. I use him only as my charismatic trader. So that allows me at least to check and reasure myself that I'm still gaining XP.