Real nice! Shutting down networking between refreshes definitely helps with the battery life. I also prevent mine [1] from updating between 10PM and 6AM. Nobody is looking at it anyway. If you search around on Github for Kindle dashboards, there's a lot of scripts out there with a bunch of battery life improvements (shutting down daemons, wifi etc.).

I built GTFS based public transit display on top of a Raspberry Pi Zero and a 2" e-ink display ~10 years ago [2].

[1] https://franz.hamburg/writing/kindling-e-ink-dashboard.html

[2] https://github.com/Scarysize/transit-pi