Of those books, I have found a few series where the first volume was either already available or available for recommendation, but then none of the rest is in Overdrive even though there's 2-5 more volumes in circulation elsewhere. Does J-Novel have a certain schedule for adding things to Overdrive, or anything like that? I don't mind if it's irregular, but it'd be nice to know how often to check if there's a pattern.
I've also noticed this - some series published by JNC are completely updated in the overdrive catalog while others (Bookworm, Villainess, Marielle Clarac, etc) are missing the most recent volumes. I would love to be able to recommend them to my library to purchase if they make it into the catalog! Thank you!