Thank you for the link to the NACA paper. It is nice to see some actual data. I would be interested to see the other paper you mentioned if you manage to locate it.

My thinking is that the "cutover" pitch you mentioned will vary dependent on prop dimension, relative wind velocity, drag/torque from internal engine friction, and resulting prop RPM. Not sure if there is a way to solve this analytically.

Keep in mind this is an airline pilot forum. The way you are going about analyzing the problem is beyond the variables a pilot can control from the cockpit. Either a prop can be feathered or it is stuck. Either the engine will windmill or it is seized.