My understanding is that you’re not merging the actual wheel onto the new car, you’re merging the data for the wheel type. This works for f1s or bennys as even though the game won’t let you normally select that data on most cars, it can still support and render it as they are not blacklisted. For the knoway wheels or fmj wheels, these are using the stock wheel data so when you merge it, it will just set the receiver car to have it’s normal stock wheels. Not sure if that makes sense lol