So although my MendelMax 2 beta2 has only minor Z wobble visible in the prints as long as the leadscrews are not constrained at the bottom by bearings, I wanted to completely eliminate the wobble from appearing at the nozzle. I also prefer constrained leadscrews, I think the bearings help support the weight of the X axis and result in slightly more precise Z movement by taking weight off the flexible motor couplers. I designed a simple part to mount to the leadscrew nuts to support the X axis without being directly connected, so that any XY movement just slides harmlessly against the bottom of the Z arms and they only move in the Z directions. Files are in