Sounds like a neat project. Yes, partial refreshes help a lot, lot, lot!
Battery life might end up becoming a problem if you intend for it to run on batteries. Compared to PaperTerm or smartphones, a Pi uses a lot of juice, but it is great for proof-of-concept!
Thanks! As you say, the Pi does chew up quite a bit of the battery life, but I hope that usage should last for at least a day or two. I plan to use a 3,000 mAh battery with the thing, which seems to be quite a lot — my Pixel 4 has 2,800 mAh _and_ that doesn't even have an eInk display! For the purposes of my project, I'm not really focused on trying to make the device extremely thin either. Something relatively chunky (like 1-1.5 cm) is sometimes quite nice and welcoming imo.
I wrote up my own notes-to-self much like the author of the PaperTerm did, which provides a brief overview of my general ideas: https://github.com/inkySystems/resources
It's a tiny bit outdated since it has no mention of my idea of using a Pi CM4. I haven't got many publicly-available info about what I've done so far with my board (seeing that it's a side-side-project of mine or something to that effect...) but it's something I'm experimenting with whenever I've got time on my hands!
Battery life might end up becoming a problem if you intend for it to run on batteries. Compared to PaperTerm or smartphones, a Pi uses a lot of juice, but it is great for proof-of-concept!