Here's an example of a toilet that acts 3D but is all 2D. This solves the problems of linework not masking textures of distant planes.
This family consists of 3 detail components - plan, front side. Solid fills are used for all of the objects.
These are then compiled into a 3D family. To get the object to project and cut correctly, two rectangles of model lines are constructed which define the imaginary model extents.