Generally people raise the middle because they want to improve the pickup. So they can remove some willow lower down and it won't matter so much because they don't often hit the ball lower down the blade. So in theory, they achieve better pickup without affecting performance where it matters to them. But the main point here is to improve pickup, with the better performance coming from improved bat speed and timing.
I don't think the same applies here. You remove wood higher up but you don't gain more power down low by doing that. And if he is happy with the pickup as is then I don't see any point in removing any willow/weight?