We don’t merge stuff from Naev anymore, no, and I would say it’s much less buggy than Naev. We try to test things pretty thoroughly before pushing out a release, and while some small bugs may of course slip thru the cracks, we’ve not so far had anything as extreme as save file corruption. (Of course, that’s assuming you don’t have faulty or fraudulent storage media, e.g. an SSD or SD card that lies about its capacity, but that would be a hardware issue if you did.)
If you do give it a try, I would appreciate it if you let us know what you think! 🙂 It’s actually quite different from Naev in many ways and we’ve been trying to develop it in a different, hopefully better direction than its former upstream project.