Your going to adjust camber to try to ensure that your using your whole tire width around the track. You can see this by looking at the tires and how they are wearing. You want to try and have them wear evenly across the width. But this is easier said then done. When running offroad some surfaces don't wear a whole lot our tires so its difficult to read sometimes. For onroad their surface is much more consistent so they can see it pretty well no matter where they are.
You can use camber to gain or lose traction like pretty much any other change on our cars. And depending on what tires you are using adding camber(adding more negative) or taking it away(adding more positive) can do either or.
What I am saying is:
Sometimes adding more camber can either increase traction in turns, because your car is rolling enough to use the entire width of the tire or it could loosen up the car because it doesn't roll enough to use the entire width of the tire. Its dependent on how the rest of you car is working in the turns.
I would recommend starting with the kit standard setup camber settings as your neutral point. Then add or subtract from there.
I start at 1° or 2°. Usually I don't change it unless I see a benefit to change it during the day.