I was able to mesh the case with your front wing by fixing the flaps.
As you can see in the picture on the left, the flap goes through the endplate. I also assigned a different ID to the second flap element. The image on the right shows both modifications.
I used session 2 as a baseline for mesh and case setup, so you can have a look at the mesh and simulation results inside my project:
I will later on compare the performance of your design with that of the baseline case.