By the power of washes my Tundra tracker is repaired.
The screws are really long, and have plenty of thread to bite into even with the washer there.

Unfortunately it's still a tundra tracker, making it useless for anything but tracking your feet.
I figured I'd have a go at using it as a chest tracker, but between the tracker itself and the tundra dongle, the verdict is a resounding nope.

At least I have a spare foot tracker I guess.