The automatic sync of photos from a phone to Proton Drive is very useful. The Drive space fills up fast though because the photos resolution is kept unchanged when backing up a photo to Drive.
It would be very useful to add a feature (allowing the user to activate or deactivate it) to automatically adjust the resolution of the back-up to save space. In the vast majority of cases, a much lower resolution than the original photo is more than enough, so this would save many users a lot of space.