I’ve stated on GitHub that I will pay a bounty of 50k sats to whoever puts forth a working PR for NIP-57 support on Btcpayserver.
I will also pay you a bounty of 50k sats if you can implement this on tallycoin. I’m sure there are others who would chip in as well.
Need self-sovereign zap support to be made available as easy as possible, otherwise people will use custodial solutions instead.