If only for this reason, lets not use our remotes as joysticks in another tele-operated period! If your design calls for buttons to be held down, you may want to rethink it to give your alliance partners a chance to send commands to their robots.
If alliances split robocoaches between the stations, use tubes to make their remotes directional, and treat the signals as commands and not a direct controller (such as "investigate that rock" and not "drive forward while I hold this button down"), IR should work. Pretend your robot is like Dave's, and on Mars. Another tele-operated period is not the intent of the hybrid period!
Having "start moving forward" and "stop" buttons would work better for everyone than moving forward while the button is held down, with the same effect. Let's practice gracious professionalism with our hybrid control designs!
That said, other mediums for command transmission would be great fun and potentially less prone to interference. Let's see the light and ultrasonic stimuli! (We might have to ask people to please not use flashlights or jingle keys near our robot
)