If there's one feature I really miss in Gitlab than the limited issue trackers. Despite Jira is still the "go-to" solution in many companies, I feel that many try to avoid that monster of a software, especially since Atlassian no more offers a self-hosted variant. I'd love to see more things like GANTT charts included (there is only a Kanban board display for issues, not yet some Waterfall or agile/GANTT board).