Greetings @MaximeJ ,
I’ve been trying different stuff in the meantime and the thing is, the problem is actually solved! I have done a very trivial fix to correct this issue but before diving into that, I would like to thank you sincerely, for your lasting support in this problem 
First of all, the algorithm you have provided above works perfectly well. This is what should be done to convert geodetic points to spacecraft frame. In the case of creating a PolygonalFieldOfView one must use this algorithm as well since we are supposed to create this polygon in the s/c frame.
Before using this algorithm one must define the polygon in clockwise manner. This solved the issue for me.
What was my mistake: I though we should define the polygon FoV just as we defined the area-of-interest on the surface of earth, which is in counter clockwise manner. This was the culprit.
Since the problem is solved here, I will adress this post in the other one.
Thanks again!