I have a 10.5" iPad Pro running Ver. 13.3, and DJI Go4 works well.
One change that I do not like - from Ver 12.xxx - is the action when I use my Apple SD Card reader. In the past, you just had to access your Home screen, plug the reader into the Lightning port, and after a second or so, the Photos App would open showing you all of the images/videos on the card. Not anymore though - as far as I can tell anyway.
For some reason, Apple has decided to go with more of a Windows feel, requiring you to open the Files App. You then select the SD card on the left, select the images/videos you want to import, and you then direct them to your Photos App. It's clunky now IMO, and a step backwards as far as convenience goes.
C'est la vie - as they say. I guess 'progress' is subjective...