The Duet 2-Series of control boards for 3D-Printers brings a lot of desirable features to the table and are one of the best boards to get for your printer right now - but display support was always sparse and thus the PanelDue was the screen to go with when using a Duet 2. With the Duet Maestro, support for the much cheaper 12864-Displays (better known as the RepRapDiscount full graphics smart controller) was added to RepRapFirmware. Sadly, this required a simple hardware modification and thus isn't directly compatible with Duet 2.