The best guide I've found so far is this one [0], as it uses easy to procure tags + guides on GitHub + offers an application to auto-upate tags via screenshot area of a website and seems like it could be done in an afternoon.
However, I'm hoping to find an even more streamlined approach that I could turn into a gift to others (assuming they want a 3rd party device on their network), where the tags sync to a raspberry pi (or similar cheap USB powered device), and it uses very cheap tags, if anyone has done this or has plans.
EDIT: I see the description now, they're called Hanshow Stellar and sell for $20-$25 a piece. Not the price point I thought of when I heard "cheap", but eh.
I ended up using atc1441's base station firmware[0] because it's a bit of a pain to actually pop open the case and get the programming pins on the Chroma 74
Furrtek has been playing with those things too. Maybe he knows things you don't and vice versa. https://github.com/furrtek/PrecIR
As a hobby photographer who mostly shoots black-and-white film, readily available info about generating grayscale images on eInk displays is intriguing from an artistic perspective.