If you were making 2D drawings with the intent of turning them into a 3D model then you would draw them to be coherent in 3D in the first place. The whole novel

If you were making 2D drawings with the intent of turning them into a 3D model then you would draw them to be coherent in 3D in the first place. The whole novelty of the research in the OP is that they're trying to reconstruct drawings that were never intended to make realistic sense in 3D. Even if AI has a place in the 2D to 3D part of a pipeline, surely you'd still want the 2D artwork be unambigously representative of what the 3D asset should look like, rather than providing self-contradictory input data and praying that the AI can magically make it make sense.