FED, that is what the thought was at SA, and what drove the initial design of the rear seat controls. The back seat collective was mechanical, connected to the front seat collective. The rear seat cyclic was a side-arm, three axis electrical, connected to the AFCS. It had 10% authority, but that authority could be “ recentered “ thru the Chinese hat beeper, on the CH-54A ( 64E ). As I recall, the AFCS control on the CH-54B ( 64F ) borrowed from the upgraded version of the CH-53 AFCS and the beeper was automatic.
In any case, there were a good number of pilots who preferred doing things from the left front seat, and had the left door and window modified accordingly ( and perhaps the left collective stick?? ). I’ve seen some movies of one of them and one could not argue with the excellence of their performance. If you’ve seen video of the CNN Tower construction, I do believe that Larry Pravacek did that from the rear seat ( Larry, along with Lee Ramage and John Holt, went directly to Erickson from Sikorsky when SA shut down our Commercial Crane Marketing operation, some years before selling the design to Erickson ).
One other note re the Crane: The US Army had interest in using it to lift the M551 Gen. Sheridan tank, and that was done, with a weight in the mid 50K as I recall. There are pictures on the internet. That was done with a B model Crane.