Just tested Revit FBX with latest updates, and seems the problems are fixed for walls/windows etc. so very nice geometry.
Curved railings/columns still need to be exported as DWG 2013 though, if FBX they have many triangles., and converting to poly´s mess them up.
In UE4 you can just select materials in the model and click the white arrow, and it will replace the imported Max ver with one selected in the material browser, and LPV is kind of a fast dynamic realtime GI so you don´t need unwrapping uv´s in Max, and setting up for lightmaps.
If you want precomputed lightning, clean/not complex geometry is good, and do not merge large/complex assets, but export in pieces if want the automatic UV generation on import to UE4, complex meshes will not autogenerate 2 UV maps, or bad ones most of the time when I´ve tried it. https://docs.unrealengine.com/latest/INT/Engine/Rendering/LightingAndShadows/LightPropagationVolumes/index.html