That community repo is a fork of the GL.iNet build infrastructure repo, just with less definitions that allow compilation to succeed.
My understanding is that infrastructure fetches the official owrt sources and applies the patches listed in the yaml files, but I didn't audit the entire build system in 15 minutes :P
This post details a community firmware with images: https://forum.openwrt.org/t/gl-inet-ax1800-new-router-openwr...
That community repo is a fork of the GL.iNet build infrastructure repo, just with less definitions that allow compilation to succeed.
My understanding is that infrastructure fetches the official owrt sources and applies the patches listed in the yaml files, but I didn't audit the entire build system in 15 minutes :P