https://unstoppableswap.net / https://github.com/UnstoppableSwap/core makers (i do not mean a SW developers, but swap providers) seems to have swap markup (assuming a fee) of around 3% which is too expensive and along with the limits on amount of traded coin pretty unusable IMO. Am I missing any makers or source for it which allows near zero fees/markup? Why such makers are not available (by default)?

I am currently using RetoSwap https://github.com/retoaccess1/haveno-reto which allowed me to place and complete the BTC and ETH exchange to XMR at 0% fee. (only paying regular Monero tx fee for a temporary custody)

How to setup an UnstoppableSwap maker? Is it this https://github.com/UnstoppableSwap/core/blob/master/dev-docs/asb/README.md . I do not see any easy to understand tutorial for layman which would tell me the requirements (evaluate the cost) + be easily understandable.