I had to google the BTC. Nifty.
I think the dome itself has less of an impact on the typing experience than a mechanical switch has on its board. It's a smaller part of the overall equation. Hold a blue cherry switch in one hand, I mean just a naked switch, and a black alps in the other and there's not gonna be a question which is which, blindfolded. Do the same with a dome removed from the i-Rocks KR-6820 in one hand and one from a Chester Creek Funkyboard in the other and they're just gonna feel like two rubber domes, with slight difference in pressure. Doubtful the two keyboards are similar in typing experience.
Actually I kinda want that Funkeyboard.
While I understand what you're saying, the switches are probably not as identifiable if you take away the shape of the stem or casing as an indicator to the touch. Because someone can identify the way a + shape feels next to a □ shape doesn't mean they could identify the way it feels to actuate the switch of all other clues were taken away.
Let's say you had 4 individual switches, a clicky ALPS, a blue Cherry, an NMB, and an IBM buckling spring. Each is presented with identical keycaps except for the mounting point to the stem (which should stay hidden under the cap for this hypothetical test). The bodies of the switches are all enclosed in a small plastic box of the same dimensions made from the same materials to hide their shape/appearance. Externally without actuation all would appear identical. I'd guess that as few as 5-7 people on this forum would be able to correctly identify all four switches from actuation of the single sample switches alone.
This would actually be a fun thing to try out, but very few of us actually hang out together, and many are on different continents... nonetheless, I think it would prove an even larger point, which is that an individual switch separate from the board assembly, and without your hands in their normal typing positions is going to be much less an influence on the "feel" of the board than many of us like to believe.
Once you start throwing in factors like, age of the switch (ALPS, especially), condition of the springs, weight and thickness of the key caps, mounting style (if mounted to PCB, then flexibility/rigidity of PCB through even reinforcement by the case), missing rivets (IBM), size of the key cap surface, layout, weight of the case, stabilizer style and condition, etc... and the whole thing becomes a mess. There are far too many variables in a board to simply label one as quality and one as junk based solely on the mechanism used to actuate the key stroke.
I'd also bet that those same 5-7 that WOULD be able to identify all four mechanical switches could quite easily learn the "feel" of the rubber domes of the i-Rocks and the Funkeyboard in a similarly set up experiment if they were given as much exposure and experience with those boards/domes as they've had with mechanical switches.