It's hard to make it 100 without it going back to 0. Maybe a gap between them and if you're already moused down going to up to 100, it stays at 100 as you continue to move the mouse right, but will go back down as you mouse left?
Completely agree, but I think the solution is simpler: just like a physical knob, don't let it cross over from 100 to 0 and back. If it's 100, you need to drag it back around the centre to get to 0.
