Check out Inkplate for larger, affordable, ready-to-program, e-ink screens - they have both 6" and 10", and even color!
https://www.crowdsupply.com/soldered/inkplate-6
https://www.crowdsupply.com/soldered/inkplate-6
I do know about epaper shelf tags but that is pretty niche imho. Not that many of us are involved in stocking store shelves.