Paul: The timing has no effect of the esc turning off. From the sounds of it you might have a bad unit, loose connection or it thermalled.
The RS has an oboard temp checker. If thermalled(I doubt unless you're not running the silver cap) while the car had no throttle input from your radio it will cycle between throttle setting(nuetral) and the temp signal.
The RS doesn't even breath hard with a 10.5 or 13.5 so something is amiss.
Make sure you run the silver cap. If you don't the unit can overheat prematurely. My second thought is what radio system you're running?
If you're running spectrum which receiver?
Most of the team guys are running 10.5s/13.5's in sensored only mode with maximum motor timing on the motor(physically). We generally run the timing bar at 100 in case of a sensor or sensor harness failure.
If you guys have any more RS or Tekin setup questions you can hit me up direct here: Rpike@teamtekin.com
With a 13.5 or 10.5 the RS Pro doesn't offer an advantage. The RS is shorter in height and slightly lighter. I would think that is an advantage.