You may be misunderstanding what FPV mode is. When turned on, even though the drone may remain level, the camera is tilted to simulate a turn in a fixed wing aircraft. What you described in your first post is exactly what FPV mode does.
What you are describing is "FPV Mode". From the manual:
Gimbal Operation Modes
Two gimbal operation modes are available. Switch between the different operation modes in DJI Fly.
Follow Mode: The angle between the gimbal’s orientation and...
While it is not always absolutely necessary, in extreme cases, leaving a clip offset for its entire duration may result in a subsequent clip from filling the frame. For example, if two sequential clips both require a positive X offset, it may...
While video settings are important, there are other considerations for what you are doing that are more important.
I've done a number of constructions sites and I am working on two more year-long projects now. Since no two waypoint sequences...