I am rooting for the SourceHut CI[1][2][3]. Along with other services it has proven useful even at the current (alpha stage). Also it's the only one that supports both FreeBSD and OpenBSD (NetBSD support is unfinished [4])

[1] https://builds.sr.ht/

[2] https://man.sr.ht/tutorials/getting-started-with-builds.md

[3] https://man.sr.ht/builds.sr.ht/compatibility.md

[4] https://git.sr.ht/~sircmpwn/builds.sr.ht/tree/master/images/...