As laid out in a previous post, I prepared an open source firmware for the ESP32 with e-ink display, LILYGO® TTGO T5 V2.4 and posted it on GitHub. See the git repository on how to build the source code.
Currently the firmware allows you to scroll through a whole book (in plain text format) that you can load from an SD card into the device’s flash memory. It also tells you your progress (how far in the book you’ve come).
But wait! There is not only the source code, I created a tightly fitting enclosure as well. You can fabricate it on your 3D printer. <STL to follow when I feel like it (-_-) >