I've wished for years that there would be an actual e-ink only laptop. Or (even better) an aftermarket e-ink screen for my current laptop, because I'm quite happy with the rest of the machine.
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https://www.crowdsupply.com/modos-tech/modos-paper-monitor
It's just a dev kit run, but I've got high hopes for the whole Modos project.
It featured a netvertible design that had a regular screen on one side and an e-ink on the other. I thought that was a pretty good idea, though this laptop had some questionable decisions, like only usb-c as IO.
EDIT: Here's an older demo of theirs: https://www.youtube.com/watch?v=XduK7wn9SE4