I don't think Devaronians particularly fit the Bounty Hunter or Technician books very well, and it isn't like Devaron is in a part of the galaxy that would get a source book. Introducing them in AoR or FaD seems out of place too.
I can see Devaronians in Force and Destiny for the simple fact that most of the species included in that are near-humans with some superficial addition to their heads.
It's annoying (a bit) reading Lords of Nal Hutta and coming across a Devaronian NPC but not having the means to create a Devaronian character. That sort of thing rubs me the wrong way.
I've felt that way since the Gamorrean NPC in the core rule book.