@stubo every time you open a gnome-terminal to its default profile nvOC runs again from scratch, it is like this from fullzero nvOC autostart method design. If you just need a shell open guake or lauch gnome-terminale with another profile. There is an alternative to gnome-terminal autostart based on systemd. Dig further in the code, the initial setup install may suffer some rough edges but in the end works like a charm, and the restart/stop commands are much more reliable.

The option in firstboot to use a different path works, but you simply can't use your user profile home as the root of a git repo. You must specify an empty folder where the m1 user has write access. Regarding the target branch name, it has to be an existing branch of the git repo. Go to github, whatever you see as git branch name is a valid string to put there, release (latest stable release, currently fed up from 3.0-stable, will upgrade to 4.0 whenever released), 19-2.1 (old dev branch), 3.0-stable (the current stable branch), 3.1-dev (the current dev branch) or any other feature branch of whatever is not merged yet, including your own branches if you have push rights to the git repo.

If you would like to write some good doc about firstboot.json options would be just awesome.