NZFF

I always thought that NOTAR was amazing (still do) but, I had no idea it started so long ago ..... like 1946!

Fascinating, Marty - first thing it made me think of was the turbo-compound arrangements on the Curtiss-Wright R3350 engines which made the Connies so great.

https://www.kitplanes.com/return-of-the-turbo-compound/

Mike

All these tail-end devices waste energy fighting the rotor torque.
As a recently energised Kaman fanboi, I rather fancy the Huskie, which uses the exhaust gas usefully: to provide lift.
Of course with co-axial rotors, there is no need to fight yaw.

"recently energized Kaman fanboi" Charl, there is help available for this.