I've created a new scene in 3ds Max that contains all the assets laid out ready for a final detail pass. I have begun to go through each asset adding any missed detail, and adding any edge loops to define where materials change. After this I apply materials to the mesh that translate into material elements when exported to UE4.
I have created another of the stone patterns that is quite widely used in the scene. I used my previous Substance Designer stone files as a base into which I plugged in a new pattern. Master material parameters should allow me to create subtle variation between different stone materials in UE4, so for the mean time I will be using the same Substance graph when I create any more stone patterns.
Continuing on the final detail pass I have completed one of the more intricate pieces of the environment, the gateway near the entrance to the level.
I continue working on secondary detail pass, and sorting out a few scale issues.
Still continuing on the final detail pass, I noticed that the upper corridors were slightly too narrow, this was fairly easy to fix however using FFD modifiers in 3ds Max. I am about two thirds of the way through this phase, and once completed I will be able to simply apply the tiling textures in UE4 and focus my time on creating the remaining textures and bringing them to a standard I am satisfied with.
I've been creating some material instances that represent all the different textures used in the scene and have started applying them to models that are ready to have textures applied.