It gets very glitchy if the pointer/finger is near the centre of the knob. Really that area should be disabled or "worked around" somehow. The hard part is you

It gets very glitchy if the pointer/finger is near the centre of the knob. Really that area should be disabled or "worked around" somehow. The hard part is you can't stop the user's finger/pointer from crossing through the middle, like a physical knob does by its physical construction. So there's a mismatch there.