Scroll horizontally in roadmap view
When scrolling horizontally left or right, keeping checking the backend to see if another epic should appear in the view based on logic of what should appear. If a new epic needs to be loaded into the view, then it might be inserted somewhere in between existing epics (per the existing sort). So the list might suddenly shift. That’s okay. Once a new epic is loaded to the frontend, then it stays there so that even though it may fall out of the current view, when you scroll back later, it can be immediately rendered again.
When you change the sort or change the Quarters/Months/Weeks setting or change the filter, the entire page is reloaded.