Using eink as a computer monitor, rather than an ereader might be rather slow. For example, many have reported that the FreeWrite, a dedicated eink writer has masses of lag. This is a link to show what the device I'm talking about
:
https://getfreewrite.com/products/fr...art-typewriter
(If you want a dedicate writing device, try the AlphaSmart Neo, which you can pick up on ebay.)
I certainly can't imagine that eink can handle video or even loading pictures (which would be shades of gray). Unless of course the technology has massively developed in the past few months.