While poking around some of my regular switch source haunts reading vague descriptions, it got me thinking about how the MX tactile space has gotten a lot more varied and nuanced since the days of “Brown or Clear?” and even since the Holy Panda shook things up. “Light, medium, and heavy” are all useful words alongside phrases like “D-shaped, P-shaped, and T-shaped”, but even those don’t cover everything.
Looking at the description of the KTT Monochrome Onyx on Dangkeebs, it uses the word “plateau” to describe the bump.
I think that’s actually a pretty great word for it. Sometimes, simple simile satisfies sufficiently.
Here’s a photo of the stem:
Now, this is exactly what I was expecting to see - not only thanks to the descriptive word they used, but thanks to having recently used it myself to describe exactly that kind of bump when talking about Akko CS Jelly Blues (which happen to use the exact same stem as these Onyx switches) and Blueberries.
(KTT manufactures many if not all of Akko’s switches - so seeing a KTT described with “plateau” instantly told me this stem would be in the switch, having seen the distinctive shape before.)
Not only do these bumps physically resemble a plateau, the shape translates to the bump experience; there’s a transition on each side of a relatively long, wide flat section. Depending on one’s perspective, this can feel like two totally separate bumps, or perhaps one very long one with a flat spot. I’d describe it as a sort of catch / detent feeling at the top and bottom of travel; you push it out of the first detent to get it started, and then it slots-into a second near the end of travel, and visa-versa on the way back up - it pops-out of one and back into the other at the top with some linear travel in-between.
In terms of switch feel, I’d actually describe Gateron Ink Kangaroos and Limbos similarly, minus the catch at the bottom of travel - I suppose those would be more of a cliff than a plateau.
Looking at the photo below, that left-most downhill slope represents the cliff face, and the little curve to the right actually represents the top; the leaf bump sits in that divot. When you push down on the switch, you first clear that sharp little peak (jumping off), and then it’s a linear fall until bottom-out:
Beyond that, I can really only think of the two stem designs (only one of which remains in production) that use this plateau shape, but I fully expect it to at least float towards the mainstream if not fully enter it. I don’t think the Onyx will be the last of the “plateau style” tactiles, and I fully expect further nuanced variety within this niche in the not too distant future.
In the image of a Blueberry stem below, the valley between the gradual slope on the left and the sharp one leading up to the top of the plateau is the leaf-bump’s starting point. Like the Kangaroo / Limbo, travel starts by pushing over a small, sharp peak - but unlike the Gat stem, this one has another sharp angle near the end of the linear travel that comes after that first peak. (The leaf doesn’t actually interact with the majority of the surfaces before and after the plateau.)
@theremingoat’s wonderfully descriptive photo of a Blueberry stem
When Blueberries came out, I think the most common way the bump was described was as a “double” bump - the two slopes on either side of the plateau. The KTT design certainly isn’t the same, but I think they’re more like each-other than anything else, and they do have that flat spot in common. I’d also be surprised if the Blueberry played no role whatsoever in influencing this newer stem. If anything, I’d consider the CS Jelly Blue / Monochrome Onyx stem design a refined evolution of the totally new approach pioneered by the Blueberry. Perhaps ahead of its time, perhaps too harsh or extra, the Blueberry itself didn’t stick around - but I do think its influence will.
I’d be surprised if this were totally accurate, but they do represent the flat spot in this diagram of the CS Jelly Blue. I could have sworn I had a photo of the stem - but for the moment trust me that it looks just like a blue version of the Onyx above. If I think about it I’ll take one tonight. 
I think KTT considers the plateau stem to be their “strong tactile” - the mediums being found in switches like Akko Lavender Purples and KTT Monochrome Marbles, and the lights in switches like KTT Mallos (and probably at least one of the Akkos, too). That said, I wouldn’t be at all surprised to see KTT or another manufacturer try lighter or more subtle versions of this bump style.
This all got me thinking not just about all the different kinds of tactile experiences now available in the realm of MX-compatible switches, but also about the vocabulary we use to describe them. Of course I’d love to see this vocabulary sharpen and become more standardized - trying to describe switches is almost like trying to describe wine.
So - along with “plateau”, what are some other really useful ways of describing specific styles or elements of switch tactility?