EPD add-on?
Congrats to this wonderful project! I would love to check if alternatively to the OLED screen an 1.1" ePaper display (148x70pixel, 30x25x0.5mm) from PL (link) could be an option too to be implemented. This screens needs 3.3V, GND and 4-wire-SPI, and two more GPIOs (which could also be replaced by software if space constraint). Which molex adapter are you using currently (looks like there are some more pins free)? Have you alternatively considered soldering FPC-to-PCB (with little holes in the FPC)? Would be happy to support with display-adapter-FPC and EPD-firmware add-on for this setup. But first lets check if you feel that this makes sense and that there is enough space available in the housing and enough GPIOs are left for SPI interface.