We probably need to define how we're using the word "telemetry", as it's being used in this thread to describe inert data (like RX voltage) that cannot effect the model's flight performance at all...

And...

It's also being used to describe "...altitude, attitude, yaw or air speed where the transmitter could, on it's on, make corrections without input from the pilot..." This type of information being fed back to the pilot from the model is already clearly out-lawed in the rules.

I don't yet own such a radio (yet), but I know others flying pattern that do. I don't know if the "inert telemetry" function (like RX voltage), can be disabled or not. If so, then CD's could just tell all contestants to disable the function if they want to fly at the contest. If not, and it's just part of the function of the TX and RX as they operate together, well, the issue needs to be thought through, or else we'll all be flying old ancient radios in a few years in order to be "legal" at events.

(-: Dave