In the scenario of having a 3D sloped floor that is slanted in a non-orthogonal direction, it is tricky to move it or the model sector as it is following the slope the model is "projecting."
To make things easier for mappers, when not add a flag to Sector_Set3dFloor which makes the target sectors uses their own origins for the slope equation? This will allow the mapper to move the model and targets freely without having to re-align them.