Yeah, it'd be great to see some more novels, but I don't think it would work trying to insert new, entire novels in between what's already there. Maybe a novella, or short stories, but novels, I don't think, would work.
Plus, JLB is telling us what's going on in this ERA of Dave and Clete's life. So, apparently, anything worth telling during these years, has been told. What would be interesting, nay, GREAT to read, are prequels...novels about the Bobsey Twins from Homicide, during their NOPD days. From the time they got home from 'Nam, onward.
Unfortunately, I doubt any of this will happen. JLB has probably already written everything (to this point) he wants to say.