I think the BB is pretty solid and if the temperatures in it remain stable then it should last. The belt is a consumable item and as such I expect it to need replacement periodically.. If either make their respective noises then it is just the three wheeler.
So you are saying that growl from the belt is normal? If so I can live with it, and happy to drive the fun little beast😊👍😎
Banging sounds must be the NVH.