What is better if the prop stops or wind meals for a wile. If you don't have a starter and you think you have maybe 10 mins left to land.?

What the heck are you talking about??

Typically when an engine quits, it does so with the propeller vertically, right in your face as if to remind you of your predicament (like the sudden quiet isn't enough). A windmilling engine could provide continued hydraulic pressure and even electricity for a bit, but in the Aerocoupe you don't have hydraulics and your important electrics run off the battery, so there's no advantage to windmilling. Aerodynamically there might be a tiny bit more drag from a windmilling prop, but that's not enough to make a difference between whether you make it to your emergency landing spot or not. At that point you need to dedicate your attention to finding a suitable spot and getting to the right point at the right altitude and airspeed to begin your landing. Any other worries about prop or re-starting should be set aside. Unless you have a reserve tank of fuel in the Aerocoupe and you simply starved your engine before switching over, it's not going to restart for you. Find a flat spot and put it down.

it used to be a practice for instructors to turn it off on a student.... usually when there was enough altitude to make it to the field.... but I have not heard of that happening in a long time...... in your example it would be extremely suicidal