Regarding the caveats on hotplugging, I solved this with a udev rule. In .config/udev.rules.d/ I created a file named 99-edid.rules with the following contents:
ACTION=="change", SUBSYSTEM=="extcon", ATTR{name}=="hdmitx_extcon_hdmi", ENV{STATE}=="HDMI=1", RUN+="/bin/sh -c \"[ -f '/storage/.config/edid.bin' ] && echo 'load /storage/.config/edid.bin' >/sys${DEVPATH%%/*}/edid\""