Here are some custom camera positions for the Horizon Simulations 787-9 GENX they are not usable with the TRENT version of the 787-9.
Those only work together with the Premium Deluxe version of the Flightsimulator and the free addon from Horizon Simulations.
Just Drag and Drop the files in the path below
C:\Users\User\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\SimObjects\Airplanes\HorizonSim_B787_9_GENX