The Music Hall clamp shouldn't continue spinning (and causing label wear) as you clamp it onto the record label. It's a two-piece design and the actual clamp disc shouldn't spin as you turn the locking knob down. Try bending the spring clip slightly to reduce the friction force between the clamp disc and locking knob.
I continue to use the lightweight clamp provided because I'm not sure what the long-term wear on the bearing might be using a heavy clamp or weight.
The disc doesn't need to have much surface area. The idea is to apply just enough circular pressure on the LP to couple the LP to the platter or mat. And not too much pressure. I found that too much pressure creates a dead sounding LP using a foam mat.
Tom
I continue to use the lightweight clamp provided because I'm not sure what the long-term wear on the bearing might be using a heavy clamp or weight.
The disc doesn't need to have much surface area. The idea is to apply just enough circular pressure on the LP to couple the LP to the platter or mat. And not too much pressure. I found that too much pressure creates a dead sounding LP using a foam mat.
Tom