Well, Boltz backend is not exactly easy to configure. They don't give clear instructions for obvious reasons, but this regtest manual is a good start. I think someone tried to make sense of it and gave up.

Also, one must be a systems engineer to run all the parts reliably. If the backend loses the database in the middle of a swap, funds can be lost forever (rescue file is of no use without a way to construct the refund transaction, and front-end alone is unable to do it). So one must run postgress with real time replication to a remote location.

But, how many alternative backends do you need? Two is not enough?