Only some have them feathered.
Free turbine such as the PT6 does. Because the Prop isn't driectly connected to the turbine.
And direct shaft engines (garettes) get put on whats called start locks by selecting reverse as the engine is shut down. This is because as you start the engine the prop turns as well because the whole lot is connected on a shaft through the engine. The requires a huge amounts of power if feathered.