ALL HAIL THE MIGHTY HYPNOTOAD!
I have only played around a little bit with franken-switches.
I have been thinking that maybe the ideal switch would be a (regular) Cherry MX Clear without as much friction, and without the tactile bump wearing out so easily. I have heard that the tactility on the Clears wears down faster with use than other Cherry MX switches.
I think that such a switch could be made by combining a rubber dome and a coiled spring together. Not one on top of the other (like Fujitsu Peerless), but "in parallel", both in contact with the same slider. The tactility before actuation would be provided by the buckling dome instead of any "tactile bump" made of plastic.
Think of a Topre switch with a harder spring.
I have put together a key module with a rubber sleeve from a Key Tronic "foam and foil" switch with a Cherry MY switch module. The MY switch has a steep force curve which I usually don't like very much, but I think that the spring's contribution to the frankenswitch needs to be very low in the beginning of the stroke when the rubber sleeve provides the most of its force and for that the MY serves its purpose. Too bad that the MY switch has so much friction on off-center key presses.
Unfortunately, the Key Tronic's rubber sleeve is too hard and provides too much mushiness after actuation. I need a softer sleeve.