The Kailh scoissors and keycaps arrived, and I mostly assembled this small keyboard, which I tentatively dubbed Edward:

(I'm still missing a few switches in there, they will arrive in a separate package.)

So how are the switches? Honestly, not great. On the positive side, they are really low. Like, this is Edward against Kamina, which is my everyday low-profile keyboard now:

The key travel is 2mm, compared to the 3mm of the choc switches, and because of the way the spring is attached in there, you are bottoming out every single time. The keys are supposed to be clicky, but they are only sometimes — because of the way the click bar is constructed, and huge play between the "stem" and the switch case, this is completely random. For the same reason the contact is not very reliable, and some of the switches are basically stuck in the always open or always closed position. It seems like they have pretty bad QE problems with them.

While I soldered and re-soldered parts to make sure the problems are indeed with the switches and not with my soldering, I accidentally got one of the switches too close to the hot air gun:

That fused the transparent "scissors" together, making the switch unusable, so I decided to disassemble it, to see what makes it... click.

Aside from and interesting rocker mechanism for the spring, the scissors and the "stem", there are two separate mechanisms inside for the click bar and the contacts:

As you can see, the blue stem has quite a lot of leeway on the sides, so it's possible for it to not touch the click bar or the contacts at all, in extreme cases — that is what makes the switch so unreliable. Apart from better tolerances I can't think about any workaround to make it better.

In conclusion, the Edward keyboard is very cute and small, super-thin, but too unreliable to be practical.