As long as the RPS is mounted firmly, does not over swing it's capabilities, and is aligned correctly with the rudder there is no right or wrong way to install an RPS.
On this particular radial drive I fabricated an aluminum piece that is bolted between the radial drive stop and the radial drive and moves the RPS's pivot point closer to the rudder post in order to prevent "over-swinging" the rudder transducers capabilities. The RPS is them mounted upside down to the cockpit sole.