I don’t understand previous post. Does that mean that their ESLs can be flashed with OpenEPaperLink firmware? Or that there is a HA BT integration for their protocol? Or that Zhsunyco uses some kind of standardized protocol that can be readily integrated into HA?
It is a bunch of search results for people who have done this before with other epaper Bluetooth shelf tags. You can either apply what they learned to your displays or use the hardware that is already working.