Earlier quoted context omitted.
Ah, reminds of the Optimus Maximus: https://vimeo.com/4294567 I also remember owning a Samsung Alias 2, which had e-ink keys so you could use it in either vertical or horizontal orientation.
The problem with all the existing products is they seem to be crowdfunding scams or they are essentially some clear plastic domes over a large touchscreen eink panel. I'm guessing that no one is able to source the 1x1cm eink screens that would be needed for a mechanical version.
They are $100 each though.