(In reference to this post:
The discussion of making a Nuvinci work on a unicycle came up several times in the 3-speed sturney-archer build project
After some mulling around I think I had figured out a way to pull this off and signed up for a frame building workshop
last month taught by Paul Brodie in order to learn the techniques necessary for building a custom unicycle frame from scratch.
It's a bit tight for time frame to write much explanation text but I'll post a series of build pictures now that should hopefully be self explanatory!
Starting here is the CAD idea that I had going into the project. The goal was to make a frame that was stiff in the direction of the chainline, since I learned from the 3-speed build that if there is much flex under chain tension, then it makes things more prone to chain skipping problems: