Weight is #1. The lens I have in mind is 3.4 kg with the shutter. The Glas for the groundglas is heavy too. There could probably be many small weightsavings, but then again at what cost.
The modularity I want is the ability to change the rear end of the back in order to allow for use with a Polaroid system or to do wet plate work or just a simple way to be prepared for what ever comes along that might be fun to try working with. I want to be open to all possibilities.