Permalink for Milestone Tabs
Milestone tabs do not change hash in browser's location. However, each tab has a permalink with its hash.
Accessing milestones with tab hash does not switch tab view (e.g. for merge requests tab):
Switch tab based on hash on initial page load. And, change hash (or query string) on tab change in browser's location.
Consider hiding Issues tab when issues are not handled in GitLab (when disabled) and count merge requests instead.
Links / references