I've walked through a full body scanner wearing a Libre (without thinking about it) which survived intact, but I wouldn't want to risk it again because I know even Library door thingies have fried Libre sensors for people in the past.
I'm more than happy to disconnect and have the pump swabbed, but if I'm wearing a sensor I ask for a pat down.
I've never had a nightmare going through security, though they always ALWAYS tell me it is sbsolutely fine for everything to go through.
My reply is usually along the lines of, "You may be right, but I've checked with the manufacturer of this specific device(s) and their advice is not to go through full body scanners, and since this thing is keeping me alive while I'm away on holiday I'd rather not risk it if it's OK with you."
The worst experiences I've read about have always seemed to be people who absolutely refuse everything, and will not disconnect for a moment. I figure, I'm disconnected for 30 minutes every shower etc. So what's the problem.