Can anyone assist, Are you able to change where the app saves images and videos on your mobile device,
I don't seem to have enough space on my phone to record a flight of about 20mins.
I do have an sd card mounted in the phone with 30gb of free space. But am unable to find an option to change the recording destination....

Thank you in advance.

Neither DJI GO 3 or 4 allow to change recording directory, there is also no tweak as far as I know. If on android check if You can move the entire app to SD-card but be aware that THEN the buggy DJI GO 4 might be unusable due to permanent crashes ....... Some android devices would allow "disk-spanning" = bind sd-card as part of the internal memory.

One for the developers to add then :-)

I have the same issue.  Videos cache to my S7 Edge's internal memory.  The 64GB HD card in the phone is pointless.  

I have the same issue.
I have a 64 GB SD card on the my phone, but have almost no more free space on my internal storage.
It would have been nice if the whole Go 4 app could be moved to SD card, and also that I can chose where the logs and cache should be stored.

I have now disabled video cache on my phone, but still the app is using 707 MB internal memory.