Has you, your son and/ or his doctors explored the possibility that he's T1 rather than T2? Not that there's anything wrong with losing some weight if it's there to lose but diabetes is not really a good way to do that! I lost 30 lbs when I was dx'ed (1984) but only weighed 150 to start with so it was pretty clearly not healthy. That particular misdiagnosis scenario is not exactly uncommon and insulin can help a lot of his BG is wildly uncontrolled to the point where he's continuing to lose weight. It seems like his doc(s) may be endorks so a misdiagnosis may at least partially explain the ongoing problems.
I didn't wear anything for years but ended up getting a guitar pick thing when I started running longer distances, figuring it would be handy if I ended up in a ditch.