detuning his contact points will help him learn how to initiate turns better because the board wont be so catchy.
Or he can learn to ride normally. You catch edges learning. Learning on a BTX board is way more forgiving than camber anyways. I've been riding since 88, I know what I'm talking about.
Don't De-tune until you are riding rails and boxes in the park. Sharp edges are good. Out of the 100's of guys I've ridden with over the years ZERO de-tuned their boards to learn on.