If you do a NMD before a Capstone Dungeon, the completion screen will also trigger an exact copy of the last NMD completion screen (with visuals of the same item rewards as the NMD, only visual though. No double rewards fortunately)
If you do a NMD before a Capstone Dungeon, the completion screen will also trigger an exact copy of the last NMD completion screen (with visuals of the same item rewards as the NMD, only visual though. No double rewards fortunately)