For my tandem 8:
I needed GIB(guy in back) to be able to talk to the flight (wingman)
Needed Young Eagles to be able to fly but not dork up the trim and PTT.
I have a switch on the panel that activates the gnd for the rear stick so I can control the GIB activities. The rear stick switch controls are dead unless I switch it on.
This sw would be unnessary for a Side by Side
Kahuna