Could you attach a picture or a link to one. I am not familiar with this and it sounds like a great idea.
I just leave the 7x17 on a big Ries or the 8x10 on a smaller Ries and carry them in the back of the SUV. As you know I go from there to mounting either in a baby jogger on top of a cooler bag of lenses over several film holders in a bag. From there I can go on trails or usually in my case along the canal towpath until I arrive at the shoot site or I see something new I want to shoot, up to two miles out. I leave the cameras set up in the garage and never have to worry about the balancing act of finding the little threaded hole with the screw.