just a quick question out of curiosity, by removing the screw of the rocker dropouts, wouldn't they be able to rotate around the top rivet/pivot 360° freely? in this case, then the belt is able to be slid on, which would remove the need of split seat stay? or am I missing something?
You’d still need to get the belt through the rear triangle; sprocket on the inside, chainring on the outside. There’s no gap without splitting the stay.
Delicate aroma of CNC yoke and rocker dropouts with split seatstay for belt drive...