Hi Marc. I totally agree. I'm still holding out hope that maybe the Arca-R or the Fotoman Dmax will have lens board mounted lenses that can also be used in a LF type camera. If you run across anything, please post to the forum.
This is the question / reply from fotoman regarding their dmax although as that camera can take a 612 back I do not think its going to be that compact!
"Hi, Just how easy is it to mount and unmount multiple times lenses from your helical focussing mounts and retain accurate focussing, as I need to use my large format lenses on two cameras..one of yours and also a standard 54 view camera. Thanks. Marc
mounting/dismounting your lens(s) from our HFM is no more difficult than doing so from a lens board. Once calibrated, the HFM will not be disturbd by mounting/dismounting of the lens/shutter.
The only caution I would comment on is that you take the normal care in not cross-threading the rear lens group when mounting/dismounting the lens."
I think in the end though like many things photogrpahic the wanted answer won't be the correct one so you'll have to end up with either two seperate and complete systems or a compromise of the two which is of course never a good idea.