For US, one thing we learned for sensor restarts, was that the software version loaded on transmitter determined whether a restart could be done without removing sensor. So similar may be true for transmitter reset. I have reset 80 and 81 transmitter days, but none since then.
In previous post I noted which 81 software version worked for me, when others were reporting that their 81 was not. (For sensor restarts).
Check this thread.
As for resets, my own experience is that it no longer worked after 81xx, but possible some later 81s with later SW version may not.