For fuselage 2,3,4, and cover 2, you will need to lower it into the bed to get rid of the connector. As seen in the photo:

You will also need to make sure supports are on, and remember that fuselage is 0% infill, flaps are 5%. Set the wings to 0.0mm top and bottom walls and 0% infill, 0.6mm side walls!

I have included g-code for Ender 3 V3 SE.