How difficult would it be to fork Graphene in order to compile it with some patches (and keep it able to self-update the way normal Graphene does, aka not flashing as a new ROM each time)? The patches would be nothing major, just small quality-of-life tweaks like re-enabling pattern lock, adding other cloud options besides Nextcloud for Seedvault backup location, etc. I have some experience programming, forking and patching apps in IDEs, etc. but nothing on the scale of an OS.
How massive of an undertaking would this be? In general, what sort of setup does one need to compile an OS? Does Graphene have good documentation on how to compile it yourself?