I've never used adb. I started reading about it when you started this post. I'm glad you made the app so I didn't have to try to figure it out.

I realize from the get-go you are addressing the Poke3 (and Poke2) and not the older models. Yes, the app works great as-is on my Poke2. It shows brightness as 40% with the light set to my normal level (pretty low).
On the original Poke, if I use Onyx light control to set a low level, then turn on your lights app, it shows 0%.
So Onyx must have changed something about the brightness control. Hey! they're getting better and the new-er Pokes are much improved!