In the Import window, "Extract scale from scale markers" is inactive if no photos are selected; but when used, works also for unselected photos
- Open the Import photos window.
- Choose a folder with multiple photos
- Select none of the photos. The "Extract scale from scale markers" will be inactive.
- Select one of the photos for import (check its checkbox). The "Extract scale from scale markers" will become active.
- Click "Extract scale from scale markers". Mildly surprisingly, the scale extraction will run for all of the photos, even the unselected ones.
Not sure what the best behavior would be, but it seems to me that if the detection is run even for unselected photos, it shouldn't require a non-empty selection. Or the other way round, it should run the detection only for the selected ones.