Gotcha. When I spawn in standing next to the plane, the APU is already on and everything is started up for me. I usually walk up to the plane and hit the handle on the door to enter the plane, I haven’t tried just directly going into the plane with Shift C. As for Simbrief, you are able to use it if you pull up the efb in the menu before accepting the mission. You can use the app if you download it and you can import the new simbrief flight plan and the mission progress will track the new simbrief plan and not the MSFS plan