That sounds like great idea, Para. I'd like to see how you did that one day if time permits.
A .2 amp increase is a good improvement.
Just file off the hex post the same thickness as the copper plate so the throw won't be affected....solder on....file it back to hex shape....and polish. That's it. The reading was 1.4 and some change and it went to 1.6 and some change. I like to fiddle around with stuff to see how it will perform because it's fun; but in essense, I might have gotten a larger/better contact with the change as opposed to the copper itself making the difference. There's no way I can know for sure; just know that setup is giving me the best reading.
Just my two cents, but I truly believe any of the button/switches will deliver a great result if they are in top notch condition.