I've read a bit about sharpening on this forum and elsewhere and it seems that -1 is too soft and 0 is too sharp and has aliasing and moire issues. In the field I've found this to be the case and in some shots it's been entirely unacceptable. Below are 2 screengrabs to show the problem.
I do think there might be another problem and could be a bug in the dji app that's causing this. When I select the "custom" mode and set the sharpness to -1, I later see that the app has defaulted to the "soft" setting and "custom" is no longer selected. Have other people here experienced this? Perhaps it's not a camera issue but an app issue and it's not possible to set the sharpening to -1 currently. Instead we're setting it to the softest mode the camera has. Any thoughts on this?

-1

David I will bring it to attention of R&D.  This has been posted on other forums but at this time we do not have a solution nor a timeframe for a solution.

David ,Thank you for sharing your obs.