Which movement to you want to use ?

If rise is the problem, and the lens rear element is not hitting the rear standard, you may be able add some “fixed” rise by making a custom lens panel that has the lens hole offset. The idea of a fixed rise is used on at least one of the Linhof wide angle roll film cameras (the Technorama 612 I think). I believe that your camera uses Linhof style lens panels. I have successfully made these from sheet aluminum using a jig saw and a file.

I use a Technikardan 23 with 6x7 (occasionally 6x9). The lens I use most often is a 47 SA, and I have noticed that I nearly always use it with 10-15mm of rise (with is as much as I can get from my non-XL version of this lens). Of course, whether the fixed rise idea would work for you will depend on your preferred subject matter and how much flexibility you want. Perhaps you could even extend the idea to making a panel with variable rise built in. Alpa and Silvestri make dedicated wide angle cameras with this kind of arrangement.