Nicehash now appears to be compatible with the Z9 Mini as well. I've been mining for an hour at 100% efficiency, will update if this changes.
Do they reward you in BTC?
Cheers
Yes, when working properly. But unfortunately I spoke too soon as my efficiency has now dropped to 20%
Nicehash has officially stated that the Z9 is incompatible with their service. It would require a firmware update from Bitmain to change this, and based on the X3 and A3, that isn't going to happen.