We've gotten requests from a couple of ortholinear keyboard makers on it. With our current Input Cover design, it is technically possible to do, but would have fixed costs that would be extremely difficult to amortize over the number of units we could realistically sell. Because of that, we don't have any active plans for this.

Would it be reasonable to test the waters with a survey or some form of group buy campaign? For example, if at least ~5k people preorder an ortholinear input cover for ~$200 you will produce one. (Or whatever numbers are required for you to break even.)

And of course if the campaign fails then you can at least say you tried.

Is there any way a hobbyist can make a custom one that would fit?

You can certainly try! Realistically it would probably need to be CNCed from aluminum, as plastic that thin wouldn't be sufficiently rigid.

How thin is the keyboard assembly?

Would Kailh choc switches fit?

Are the external dimensions and body interface points of the keyboard assembly published anywhere?

I would be very interested in having a programmable ergo keyboard like the Ferris: https://github.com/pierrechevalier83/ferris

The problem is mainly getting switches (and their keycaps) that are thin enough. All the switches that are available to be used by hobbyists (Cherry MX, Kailh Choc...) are way too thick.

I'd hope for a thicker laptop frame, then.

I think a frame thick enough for PCB + Chocs would then allow both a premium mechanical keyboard in a standard shape, as well as allowing for swapping this out for whatever more niche arrangements.

Whereas, for a thin, non-mechanical keyboard, the manufacturing cost would be too high to be feasible for anything but standard, presumably.

This would be fantastic for a larger-size laptop (desktop replacement size).