George
I don't think you have truly explored the way your marzocchis function. You will either have three holes spaced 50mm apart in your compression leg or a slot. You have valving on the damper rod and the check valve at the bottom is purely for refilling the cartridge. The holes or the slot produce your damping and the valving on the damper rod assists with the lower portion of the stroke, once the piston has passed the final orifice. The marzocchis are a terrible example of suspension engineering, employing poor quality materials combined with lousy tolerances and a damping system that was obviously a discarded school project. The forks suffer dreadfully on the MX track and you can forget about clearing any triples. But in spite of all of this they have won the praise of the enduro community. Trail riders love the things. They can be revalved and improved with great results. WP produced the 50mm Extremes with compression valving on only leg on some of the LC4 models. Nothing fancy, they simply left the shims off one side. If you made the comp valve a simple check valve and used the midvalve for your damping you would end up with cavitation within the cartridge. You would have to have resistance for the valve to work against. What you propose would require a design similar to a twin chamber fork. Unless of course you made the base valve a one way valve (refill only) and the adjusting curcuit would have to handle the rod volume. I think this was tried in the 91YZs. Only they had a small bleed at the top of the cartridge as well.
Regards
Terry