Yes there is a bit of wobble, but not to the extent of a rocker plate.
Maybe similar to the rubber feet on the latest gen Kickrs?
I use mine powered, because I can, and it adds road surface emulation and downhill emulation, but irrelevant for structured workouts.
It was my choice as it can work unpowered for race warmups.
The light goes red when you’re working harder, and illuminates the puddles of sweat and tears.