Donut dipping the spring will eliminate the bit of spring ping the switches tend to have, and lubing the rails, back and pole of the stem will rid the switch of this sort of natural "resistance" nylon has, kind of like wet finger across glass.

I opted to just focus on the stem and spring, without touching the housings, and it worked out pretty well to bring out the roundness of the early bump.

Of course, the nylon helps give the tactile switch a sharper drop past the bump, which you may or may not prefer. I'd say if you're curious-- try a couple!