The refresh rate on e-ink is so low that coding on one would probably be excruciating. You should think of it as a replacement for paper, not a replacement for a monitor.
If your laptop isn't very bright, you're mostly out of luck. You can work in the shade, try polarized glasses, buy a brighter laptop, or find a portable monitor that is brighter than your built-in panel.
> If your laptop isn't very bright ... buy a brighter laptop ... and a portable monitor that is brighter
As someone who works with my laptop outside in the sun a lot, the trick is not to have a brighter laptop but to have one with a matte display instead of glossy, and use bright backgrounds for everything. Even when I'm in direct sunlight, matte display and light themes make me able to see my code without any squinting or troubles.
> The refresh rate on e-ink is so low that coding on one would probably be excruciating
If you've edited files in vim over a spotty SSH connection and wasn't phased too much by it, you could probably survive the e-ink refresh rate as well.
Probably. It seems the X1 Carbon (the laptop I have) has most editions with anti-glare screen though. Found this site that could be helpful for people looking for matte displays: https://www.productchart.com/laptops/sets/1
If your laptop isn't very bright, you're mostly out of luck. You can work in the shade, try polarized glasses, buy a brighter laptop, or find a portable monitor that is brighter than your built-in panel.