I'd love an accessory that makes a keyboard completely flush with the surface it's on. I get this is hard because dimensions are different for each keyboard, but something that e.g. a Macbook fits into would be nice, given its standard size. Everyone's different but for me personally, I feel that would be a big ergonomic benefit. Supported by the fact that my current winner is the one coming closest to this ideal, being extremely low, maybe ~0.4cm from the surface.

Been toying with the idea of getting something 3d-printed, basically something just as high as a Macbook, that you can attach to the front of it, giving a flush surface. Even better would be carving a Macbook-bottom-shaped or external keyboard-shaped "recess" into a table to place it into.

Ever seen or heard of anything like this?