I think many of us in the more tech challenged camp would like to see what you come up with.
Please keep reporting!
The biggest issue with SB C models is that they use the lead screw for feeds, which rapidly and selectively wears the leadscrew out, making it useless for thread cutting. (secondary issue is no power cross feed).
Real metal lathes separate the longitudinal feed function which is most of the wear time on the ways and other components, from the screw threads. This includes a gear train in the apron, which drives against the rack under the front way of the lathe. In higher end machines, this is through a keyed "feed rod" and the leadscrew does not turn at all. For lower price point machines, the keyway is milled into the leadscrew, and the leadscrew turns to drive the geartrain, which, opposing the rack, slides along the leadscrew but does not ineract (bear on) the leadscrew threads in any way.
If your leadscrew is unworn, there might well be some advantage to the un-keyed C version for adapting to threading only. Presumably it can be mapped, and accommodated in the software to yield more perfect threads than any mere mechanical drive.
OTOH if the threads are still used to drive the carriage for feeding for all normal turning work, then it will wear and might need occasional software tweaks to keep the threads accurate "everywhere" in the carriage travel.
smt