Given how able the SmartThings app is, and that I can find my headphones, tablet, phone and watch all from each other, I'm really surprised there isn't a 'Find my One Remote' option.
Honestly, with it's slim profile I lose my One Remote at least 3-4 times a week.
I'm contemplating adding a SmartTag to it for this exact reason, I'm just surprised it doesn't have a tracker, or at least an audio beacon, we could use!