GitLab is used only for code review, issue tracking and project management. Canonical locations for source code are still https://gitweb.torproject.org/ https://git.torproject.org/ and git-rw.torproject.org.
Quick Start is available on the Connect screen, but we don't expose a way of disabling it when it is enabled.
I don't know that we'll have time to fully implement it before releasing 10.0.
