I still think if you put the sensor/transmitter on a piece of hose, clip a wired receiver right next to it, like mask strap or shoulder D-ring, you could get away with a basic radio signal... Of course if you're using a wired receiver, why not just have wired sensor. Rebreather people don't seem to have a problem with fischer connectors, why can't OC divers have a wired hoseless AI.