Whereas I don’t have any experience of it, I’m led to believe that the ‘Manual’ function within the DD app does allow you to change the camera settings. I’ve yet to try it, and probably won’t as I’m happy with the way I manage my flights.
I don’t have any problems setting them with Go4 and switching to DD whilst still in the air. There is no need to land between fixing the camera settings in Go4 and starting a mission in DD.
Furthermore, the only setting I have found that needs resetting after each battery change is the focus. The exposure settings are maintained in Go4 after each change.
You don’t need to land between missions either. I’m still using the traditional method, which is to after a mission, switch the RC to S, halting the drone in the air, close the app down, switch the RC back to F, restart the DD app and select the new mission. If you need to set the camera up again, of course you will need to go back into Go4, but that can all still be done with the drone in flight.