Sheld, I had this question in my last pm to you, you forgot to answer it (no worries, I know you're a busy man) but I thought that, instead of sending another pm, I should ask this in public in case anyone else is interested.
Both my previous bass and my Prima (bart-loaded) have a blend knob. I have learned to get my tone with it, and I usually have it either on 2/5 or on 3/5, close to the middle but a bit towards either the neck or the bridge pickup. On the other hand, I really liked the series setting on other Dingwalls I tried. So, this is what I was thinking. I understand that a blend knob and the option to go series is most probably out of the question, plus I will most probably get the usual volume drop in the middle position, but is it possible to have a volume/volume configuration and an additional parallel/series switch? In this case, would it also be possible to control the volumes of the two pickups in series mode as well, resulting practically in a blend while on series? I don't really know how pickups are connected, but I was thinking that, if each pickup and its volume pot were thought of as one thing and then these two "things" were connected with a parallel/series switch, it should be possible...