As I did not have had the time recently to play around with the latest SCM-Manager versions so I might suggest something already (partly) there. If so: sorry for the fuzz.
Use case: developing various tools/script to support a project/product. These are seperate items. They might not interact and can be developed next to the main project.
I have not used this feature yet (bit want/need to), but as I understand there is some support for this with Git:
Having a nice GUI to facilitate this would be nice.
#2 (wiki) documentation
Sometimes it can be useful to document something which applies to several projects/repositories. Such as links to tools, document coding standards, who to reach out to in case of X, knowledgebase like things such as what is the IP-address or hostname of the development/test database server etc
It would be nice if such info can be jotted down and shared among multiple projects.
Obviously it would be overkill to implement a full wiki. It would be better to support an external one or to minimize the feature.
#3 sync/backup/publish repositories
Develop in house some code using SCM-Manager and publish (export) it to external GitLab? Have a FOSS project on Github with a local SCM Manager enterprise sibling and import some code to SCM_manager?
Both are examples of one way code sharing, but copying code between branches manually or automatically could keep codebases in sync. Though cookie as the more complex it gets the more challenging conflicts can be.
Never the less a nice feature to have.
When available through an API it can also be used in backup script automation.
#4 License wizard/manager
Finding the right License for a project can be challenging. You also need to add a license file. Some licenses allow for double licensing or a change of license en some do not.
Having a simple plugin which would assist in these would be nice.
Thank you for a great project. I liked SCM Manager v1 a lot, but things are put really into high gear with SCM Manager v2.