Next up was the spring in the switch. I'd still love to find a brass/copper "hot spring" to try here but I've found that even the steel spring that it comes with can be tweaked to work better. I actually used a spring I found at my local hardware store that is *identical* to the stock one, except it is perhaps 1/4 of an inch longer. I think this would work with the stock one too, in a pinch.
I took a pair of needle nose pliers and stretched the top most coils, furthest from the bottom, in effect making the top half of the spring slightly wider. It takes physical effort now to insert the spring inside the button assembly... not much but it's now large enough that at least part of the spring is *always* in solid contact with the locking ring and thus the rest of the button assembly. This worked great and got rid of the occasional "hot button" and misfires I was having. The only problem I ran into is that if I used the lock sometimes the very top most coil would then get trapped between the lock and the delrin, preventing the lock from screwing all the way back in again. A little more work with the pliers and I fixed that too. The spring is now sort of egg shaped, a bit wider in the mid section than at either end. I smeared a dab of Ox-Gard on the inside face of the locking ring as well: