On my rack I'm splitting the 1/2" shaft so I could sync the 2 pinions. I thought about building an indexing plate or degree plate (like they use for timing cams or something) but will start with an extra large shaft coupler. If it slips once I get it synced up the shaft might find itself welded to the coupler
But anyway..
Looks like a good idea although I'm not a big fan of the dual shaft method..
b.