Tried them on a feather years ago. Getting them to reliably work was a no no. Worked around 50% of the time if you were lucky. Too easy for another machine to pin you against the wall.

And yes spinning weapons are not allowed in heavyweights as the arenas can't contain them. If you want a spinner you are building a featherweight as only the robochallenge arena can contain them which is a feather only arena.