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).