In most respects a spinning prop behaves as a disc and the thrust on it could be related to that on a smaller disc.

There is another phenomena with a spinning prop that tries to keep it pointing directly into the wind. I think it comes down to the same thing that makes a vertical axis machine work on both sides when one blade is going what looks to be the wrong way.

Under the right conditions a horizontal axis up wind machine will keep running up wind without a tail. The condition is unstable and when it reaches a critical angle the seeking force vanishes and the thing turns down wind.

With the usual alternator offset type furling scheme, we normally think of balancing the torque due to thrust about the offset against the tail steering moment. If there is a force trying to keep the prop into the wind then this seeking force needs to be subtracted from the thrust. If the seeking force exceeds the thrust then it will never furl. Normally there is a state up to about 30 deg to the wind where there is no significant reduction in power and the thing looks to be furling with the tail partly bent. Beyond this angle the seeking force drops off and the then thing becomes dominated by the thrust and true furling takes place.

Changes in operating conditions can sometimes delay furling to a high wind speed or cause it to fail completely.

Because the seeking force vanishes at some angle, most furling schemes cause a significant drop in power in the higher winds. Unless you produce controlling forces by more complex methods than a hinged gravity controlled tail, I strongly suspect that any machine that doesn't drop power in high winds is failing to furl.

Under turbulent conditions a furling machine will occasionally get caught out and deliver a high burst of power but the general power level should fall significantly when the tail goes beyond about 45deg.

This is an aerodynamic issue and is not related in any way to the gyroscopic things that others seem to be in a muddle about.