Xmas was yesterday now for me, but I never went outside the house. I made baklava ice cream and a green chile cheese ball, petted the dog and the cat, wished it wasn't raining so I could take a walk, and my mother bought some sugar that we needed at a pharmacy.
I haven't used a SPOT for ten years, but at that time they were pretty limited in their comms. They weren't on if I didn't want them to be on, and even when in and supposedly with service, were flaky. Now, I use an InReach. It has more functionality than the devices in the past, but the connection isn't really any better. All of these devices were owned and managed under government contracts but I don't think they would be any different. I have never used them to track myself as I go, I use different equipment for that.
Long story short, you'll worry more about getting service when you need than you will about being tracked when you don't want to be. A tree canopy or tall canyon can prevent comms.
This would have been avoided if the child's ticket was scanned, which I can only assume must not have happened. I imagine this type of error isn't something they want to talk about any more than misdirecting a kid to the wrong destination.
My main use case is with folks who have Apple phones. LocalSend has interoperability there. I cannot speak to Android-Android transfers with it, but have used the nearby share in the past.
Sorry for being confusing - have you dressed Charlie up as the unicorn? I feel that it has been long enough to not be cliché.