Thank you for your reply Adam. I did try importing the model into UE4 through datasmith. The geometry, and some of the materials surprisingly, came out intact. The problems arose with mapping and generating collisions, because for whatever reason, the archicad to 3ds max import does something strange to the meshes, in that they don't come in as mesh groups (defined slabs, walls, and so on), rather as individual entities. I can prevent that by exporting the model from archicad in the .obj format, but then everything comes in as groups, as I linked in the images above. But I suppose working with two or more formats means a lot of cleaning up is needed regardless.
On that note, if I were to export the model from archicad to 3ds max in groups (walls, slabs, roofing, furniture etc.) separately, do you think I could sort of, for lack of a better word, assemble it all in UE4 and start the viz process?
I haven't asked them about datasmith for archicad, but if they do release it, it would make the workflow so much easier. I'm actually trying to get the office to incorporate UE4 and VR as our main archviz workflow, and there are so many hurdles haha!
Thank you for your assistance Adam. Greatly appreciate it.