I have T2 and self fund for CGMs. Firstly the libre2 and now I’ve settled on the dexcom1+.
I’ve only had a problem with one out of eight Dexcom sensors and that’s when the calibration failed and basically got stuck in a never ending cycle for days. The sensor still worked.
It comes with an additional adhesive patch which I’ve never had to use. Honestly I find it hard to peel the sensor off my skin when it’s finished. I always use an alcohol wipe prior to fixing the sensor.