The working door is nice and yes if you’re actually ducting air thru the fuselage like mine then it will work. Have you made a duct tube like mine? If not then let me know and I could make one for you.
I plan to make a servo mount that goes on top of the duct with a control linkage to operate the door. I was not happy with the shape of the door, it’s too round, so I’m also modifying the door to look correct.
There is a company that makes a thermal controller for servos to move cowl flaps. I’ll post the info. It’s temp driven and can be controlled by the Tx.
I was debating on making the door operate based on throttle position or temp depending on how the engine ends up running.