Premixed front light causes a fatal error on Kobo Libra 2

[ticky]

If #237 is patched, the next error we get is one about the frontlight subsystem; my Libra 2 does not have the /sys/class/backlight/lm3630a_led/color front light LED, but the /sys/class/leds/aw99703-bl_FL1/color currently only used in Plato for the Sage

I get this error:

Error: can't build context

Caused by:
    0: can't create premixed frontlight
    1: No such file or directory (os error 2)

Is the use of the /sys/class/backlight/lm3630a_led/color for the Libra 2 based on known-good information, or is there something I can do to help disambiguate hardware revisions?