Having had my Mini 4 Pro returned to me last week with a brand new RC 2 controller I was able to continue testing the 4G dongle. I took off from my garden and flew over a hill losing contact with the O4 signal. Immediately the 4G dongle took over and I didn’t notice any delay in transmission/loss of FPV. As it was a very rural area in which I was flying 4G contact was weak at times and lost on two occasions resulting in the Mini 4 activating the RTH sequence. However when 4G was acquired again control of the drone was re-established immediately. At the end of the flight activating RTH the Mini 4 returned to my garden and landed as normal. I still have more testing to do but overall I am pleased with the 4G dongle and it does work.