One thing that you might try, that won't harm the guitar, is to cut a piece of thick felt, slightly smaller diameter than the knob. Pull the knob off, and place it underneath, to create some "soft" tension.
Questions...
1. How do you remove the knobs if they dont have the little allen head screws on the side?
2. Since i dont use the tone knob (only on full) but i use the push/pull on it for coil splitting, is it not too difficult to put some sort of switch in its place instead?