Couldn't just about anything that the spy brings next to the field be a "signalling/pointing device"? I'd put good money on at least one team bringing something (not necessarily used as a pointing device) outside the box and having it provide a competitive advantage. Maybe a 6 foot wide mirror to 'signal' to the driveteam so they can see if there are any boulders hiding on the far side of the defenses, similar to
1986's mirror in 2010?