Bambu never put a blanket ban on just any TPU: Their wiki says the printers can handle 80A/30D or harder, and the AMS can handle 55D/98A or harder.
There are some reddit threads where people have listed brands/types that worked or not. I’ve been meaning to experiment with it but haven’t had the time yet. I noted from some such thread that I might want to try Overture High Speed TPU 95A, Extrudr Flex Hard TPU 58D and/or Priline black.
My use case is printing seals in place. I do have some CC3D TPU 98A but didn’t try it in the AMS, I might do so but to me it feels just as soft as Bambu’s 95A.