Drawing the Flight Line:
One can manually draw a line within flight hub 2 that can be sent to the remote controller for automated linear flight planning.
Could also draw out the flight line on the remote controller.
Could also import a polygon into flight hub 2 and draw over it.
Should lines be split up into smaller sections or just one big one?
Take into account how operators will be flying the flight lines in planning if you want to have one big line or smaller segments.
If working as a single team in the field find one longer line to be easier. You can just keep working your way down the linear sections and utilize the custom breakpoint tool of linear flight to resume at a specific location. Just important to keep track of which sections have been completed in case you accidentally cancel the flight and need to select the breakpoint to resume from yourself.
I think it is easiest to split the line into smaller assignable segments if working with multiple teams but if it is a pain to do this, could also do this when actually making missions.