Yes, the p70R will work the same as the ST8002 control unit on a sailboat. The main reason why the knob control heads are directly related to power boats is because you don't have the Wind mode options with the rotary knob control heads.
Re-awakening this thread, if possible. On page 33 of the "81355-1-EN p70 p70R Installation and operation instructions.pdf", it describes getting into Wind Vane mode by hitting Standby and Auto at the same time, and this appears to apply to both P70 and P70R. Is that true? I can see that the knob doesn't appear to provide an alternative to AutoTack and AutoTurn, but one can still enter Wind Vane mode on the P70R, no?
You can only get into these wind vane modes using a p70.
If you can't auto tack with the p70r then what is the reason that some sailboats elect to install it? Can you program another soft button for tacking?