@Lingwisyer & @Barry Kelly
I think I have just found the solution

, that can by pass my problem, but it's not optimised

although it will work perfectly.
This solution needs a little bit of imagination.
Solution:
- First, create 2 groups, one for the object in it upright position "object_untrimmed", and the other for the cutting plane & the previous defined group "object_trimmed"; all at the top of the "3D Script".
- Second, always place the group "object_trimmed", that way you will always get the correct cut plan representation in plans.
- Third, create a parameter for activating elevation on plan.
- Fourth, in the "3D Script" create an "if" condition that will place the "object_untrimmed" rotated around one of the X or Y or Z axis.
That way you will always use the same "PROJECT2" (or one of its variants) for the same purpose view type.
- Fifth, in case you need to modify the Elevation on plan in the 2D view, you will have to remember that you will have to control it in the "3D Script".
- Sixth, don't forget to kill the groups.
Please if you have a better idea than this one, I will gladly hear/read it.