I wasn't aware of this phone or this person before reading this thread, but found this: https://gitlab.com/iode/ but I'm not sure if that's everything. I found that link at the bottom of https://iode.tech/ which I found from a search for iodéOS which is what is claimed to be the OS.
@sam@solarveggie@Asbestos No, that's not what is being asked. Where are the sources for the OS on each of the Brax devices? We're not asking where the sources are for the operating systems they forked.