Pardon me for asking silly questions, but why doesn't armbian just maintain one master clone of the upstream git repository with branches set up to track all upstream branches for the boards, then just fetch from the master branch locally? I am trying to create a patch based on the Collabora WIP patches for V4L2 HEVC work, and dealing with the build script re-fetching the mainline kernel from the master repository is just too much. So I have cloned the tree myself into my home dir, and changed lib/configuration.sh MAINLINE_KERNEL_SOURCE to point at the $HOME/linux-source/.git directory. Armbian then takes over and does the full clone locally, and I can tweak/rebase my local copy as needed, without needing to change OFFLINE_WORK and dealing with refetching different current/edge versions.