It would be most cool to integrate all these services in some way. Phabricator,
DocDokuPLM InvenTree, and Matrix/Discord all have APIs, I imagine BookStack will have one eventually.
I think it would be mostly useful to pull stuff into Phabricator then push out notifications from there to Discord/Matrix. It helps that Phabricator supports extensions.
SSO would also be a nice feature to have, having three separate logins is kind of annoying.