I have an iMac 5K (mid-2017) and a USB-C to HDMI adapter. I used to have a standard 24-inch monitor (1920×1080) connected to the adapter, and it worked flawlessly. However, I have a video capture device interposed. While this device supports 1080p resolution, macOS recognizes it as running at 720p as native resolution.
I can force macOS to run this external device at 1080p by selecting the "scaled" video modes (and it seems to output a correct 1080p signal); Each time a video configuration change is made to macOS (such as when switching between mirroring and expanding the desktop), the default value is always reset to 720p.
Basically, it's always "best for viewing," but the opinion is that this setting is 720p and not my preference for 1080p.
Is there a way to force macOS to change its default resolution for an external device so I do not have to manually change the resolution each time?