The only winning move is not to play. Mapping libraries, even with source generators, produce lots of bugs and surprising behavior. Just write mappers by hand.
So far, there have been no surprises, and the library warns about potential issues very explicitly, I quite like it.
Of course, if it's just a handful of fields that need mapping, than write manually is the way to go, specially if said fields require a custom mapping, where the library would not facilitate.
It was meant to enforce a convention. Not to avoid the tedium of writing mapping code by hand (although that is another result).
This describes more than half of .net community packages and patterns. So much stuff driven by chasing "oh that's clever" high - forgetting that clever code is miserable to support in prod/maintain. Even when it's your code, but when it's third party libs - it's just asking for weekend debugging sessions and all nighters 2 months past initial delivery date. At some point you just get too old for that shit.