I currently have an Air 2s and find I can digitally zoom 2X without much loss of video quality. I like to do this when tracking my kids. The Air 2s has 5472 pixels horizontally to deal with, meaning the 4k video is nicely oversampled until about a 1.4X digital zoom. Digitally zooming further...
Zup peepz!
I shot some stills with the mavic pro the other day, and needed to crop them in post due to poor framing. If I were aware of the long distance between the subject and the quad when I shot the images, I could zoom in a little, but to my understanding, you loose the same amount of data...