Anyone able to get the pro to feather while in flight, ie; stop spinning? I close the throttle, cut off the mix and and bring the prop lever all the way back but its still windmilling. Thanks

Does this help you? It's from the manual "Flying Guide".

To shut down one or both engines, first reduce the appropriate throttle to idle, then reduce mixture control lever/s to zero then pull the levers back again. At this point the engine will not be firing but the prop will still turn, with appropriate sounds to indicate they are doing so. To completely feather the props (stop them turning) and thereby reduce prop drag, pull the prop lever or levers fully back then pull them back right to the red zone. The propellers will then slow and stop, whereupon you will hear just the ambient wind noise.

I remember practicing some single engine ops when I got the Duke, so (from my memory) the not spinning prop was something that could be achieved.

In real life, you can eliminate most of the prop drag without the prop going to full feather. I've flown many piston twins but not he Duke and have only shut one down. It's possible that in the feathered position there is still a little prop angle to continue windmilling unless engine has seized up.