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.
Sponsor F deliverable 22 is about implementing one or more datagram-based designs and experimenting with them based on the mid-March testing plan. We'll discuss the details once deliverable 3 (#4683 (moved)) is done. Steven says he's going to lead this deliverable.