At the moment, the only place we can add a manuscript flag is from the manuscript information screen. It would be really handy if the flags option was carried over and available on multiple tabs/tasks in S1.
Flags are used in a variety of different ways and can be used to pass information back and forth between teams. Quite often you will find yourself having to go to a different space on the article and when you need to add a flag, you are always having to return to the main information tab.
Notes are available on multiple tabs/tasks so it would work in exactly the same way.