There is apparently a grand total of one non-human species with hyperdrive technology in the Honorverse, based on comments made here and there in the past (I checked the Infodumps but no mention was made). If I'm remembering right,
1) They're an alien species adapted to a particularly hostile natural environment - at Honorcon 2013, David described them (paraphrased) as 'similar to the Quarn, but not quite as extreme), so they don't overlap with human-occupied worlds.
2) They were 'uplifted' in a way, gaining hyperdrive tech from humans.
3) They have a small cluster of planets down on the far opposite edge of the Solarian League from the Haven sector, way out on or beyond the Verge.
But that's all I tentatively remember. They're a mystery, and mysteries are interesting. Obviously, being so primitive and far away - not to mention completely un-cuddly - means they're not really relevant as anything besides background detail, and would distract from the human-focus stories by being major players/plot points. But will these mysterious unnamed extra-terrestrials ever actually appear in a canon novel, even in a cameo role?
and, Mangy Fur the Smart Alick Spacecat.