I don't suppose there are more than about two or three people on earth who care, but I just figured out an etymology that's been puzzling me for a while. In Kwaṛandzyəy, the word for "genie" is agwəḍ, plural igwạḍən. It looks Berber for its form alone, but I had never found it in any dictionary - until now, going through Taine-Cheikh's new Zenaga dictionary, when I came across ugṛuđ̣an (original singular *ugṛuḍ) "démons, diables (plus dangereux, plus forts que les autres)". It turns out to have been borrowed into Hassaniya too - īgṛäwṭən. The loss of ṛ is more or less regular in Kwarandzyey (usually it's restricted to intervocalic positions, but there are a few other examples like this); so is the shortening of a long vowel to ə in a final closed syllable, with a w remaining to indicate its former quality. Quite possibly the next commenter will tell me that actually this word is well-known in Kabylie or Morocco or something, but for now it's another piece of evidence for my claim that Kwarandzyey includes a number of loanwords specifically from the Zenaga branch of Berber.
UPDATE: see comments - it wasn't the next commented, but the third one who established that this word is attested in southern Morocco too, which makes sense both since that region is also fairly close to Tabelbala and since it tends to be easier to find Zenaga cognates there than further north or east.