Requests for additions to gitlab-ctl would need to go into GitLab’s system, not sure the perfect place but maybe start with https://gitlab.com/gitlab-org/omnibus-gitlab/issues?
Mattermost is design as an archive, so there’s not a straight forward way to reset the database right now. We’ve created a ticket to track the addition of a “Reset Server” command to ./platform that could do something similar to what’s being requested of gitlab-ctl: https://mattermost.atlassian.net/browse/PLT-975