Separate (multiple) 2D / 3D viewports
The idea was coined by user Retry on the forum here:
The request is to faciltate the ability to check the work immediately on a different screen with a different camera. The most obvious example is being able to paint in the 2D view (UV view) and seeing the 3D view update; preferably on different monitors as well. As Retry's example outlines, painting on the Cintiq and seeing 3D viewport updates on the second monitor.
An example from Mari, it allows you to view your work simultaneously from different angles practically immediately after "baking" the paint strokes. This makes for a very smooth experience when dealing with shot-based texturing.
Bea Carbó 0 commented
It will be helpful