Previously, there was a theme called hcLayers designed for E-Ink screens, but it seems to be outdated and no longer compatible with newer versions of Locus Map and OpenAndroMaps. Currently, information about new themes specifically for E-Ink screens on Locus Map is quite limited. But you can use the method in Locus Map, you can adjust display settings such as contrast, color and brightness to better suit the E-Ink screen. This can help improve map readability and display.