Hey, you're doing a beyond amazing job for somebody doing it on their own, in fact the quality is pretty much like any other big group! If you're having fun, don't stop translating manga, nobody can tell you what to do.
However, to prevent drama, maybe try to talk something out with NASS? Or discuss maybe shared translating, as in you do one chapter, they do the other etc, since they seem to have a lot on their plate. I've read the comments down below, and although I love NASS translations, it's also true that this story hasn't been updated in a while, so it seems fair if they can settle on a compromise.
Whatever happens in the end, good luck!