Hi,
Regarding 59z, the stability of the lift is not only entirely dependent on the latex on each side. Although an equally tensioned latex system is a precondition to a stable lift, a lift can still wobble/sway to considerable degrees.
It isn’t easy to give one magic solution, but making sure all joints are equally tightened and an overall good build quality are imperative.
If you were to look at 1.12 of the reveal video, you would be able to see a very thick piece connecting the upper section of the rd4b. It’s what we call a magic bar- two c channels screwed together to virtually eliminate twist. This does help with the stability of the lifts also.
Perhaps this thread may also be useful: