@cstross
I would suggest moving now and buy yourself time to fix all the jiggly bits that bother you. Or perhaps look at #OpenDarwin or an even better option would be #PureDarwin. You still get the NetBSD, but it is a bit closer to your existing MacOS.
@cstross
Just saw another potential MacOS replacement... It's called #RayvnOS at;
https://ravynos.com/
They say it is in pre-alpha so prolly not somethin you are interested in, but thought I would post it just in case.
I think I might install it in my #Proxmox server when I get it back online.