Actually, just having your electronics on causes interference with beacons. That has already been proven. The general guideline is to keep your devices at least 16 inches or roughly 40 cm away from your beacon. I've played with it enough to say that there is an effect.
It all comes down to how you use your gear. Keep in mind that if you get into a beacon search situation, one of the best practices is to make sure you turn all of your electronics off as part of your search checklist. The problems seem to be with interference to the searching beacon not the transmitting one.