“Rich black” in CMYK is one thing, but not what I was talking about. Am I misremembering that some really old inkjets used to be just “CMY” (or maybe a slightly different set of three pigments, but either way no K) where they had to mix all three to get an approximation of black, and do any like that still get made?
(It’s been long time since I’ve paid attention to any kind of printers other than lasers, LOL.)
I’m still using an Archer C7 running OpenWRT that I bought years and years ago, and I like it well enough that I also bought one for my parents and a couple more as backup (when I found them for ~$10 on clearance).
If the AX23 is just an upgraded version that is otherwise similar (i.e. can also run OpenWRT)—and I have no reason to think it isn’t—then I would consider it a fine choice.