Best way to manage sprints?


I have a use case whereby I have multiple planning boards (basically different projects that we’re responsible for) and then a single milestone for the current sprint.

The idea is that we’ll take the highest priority issues from different projects and feed them into the current sprint milestone. This works really well as a workflow, but it’s a bit of a pain in gitlab as I’ll need to go to each of the project boards and add in the new “current sprint” milestone and remove the old (now closed) one.

Is there a better way to manage this? I could use labels, but milestones have the advantages of having dates strongly tied to them, and burndown charts.