Theoretically, if someone would build it:Buckling rubber sleeve in combination with a spring that has a steep force curve.
Rubber can add tactility without adding scratchiness.
I found that vintage Key Tronic foam-and-foil with buckling rubber sleeve actually felt very nice when taken apart and typed without the foam, albeit being maybe a little stiff. Replace that foam with a cushioning spring instead, but one which does not dampen the rubber's impact on feel too much, i.e. has a steep force curve.
In real life, among switches that exist:Sorry. They all suck. Gateron's work like MX. Clicky Flaretech is hardly noticeable.
Interesting things that perhaps could achieve what you are looking for but are not optical:• I would like to try putting vintage Key Tronic rubber sleeves into Leopold's new foam-and-foil keyboard (which has different foam than vintage switches, supposedly)
•
Input.Club Silo Command hall-effect switch.