A while back ago I had collected about ~100 different 3D mechanical models from various CAD libraries I had found online for a personal hard-surface collection I was working on.
At around the same time, I had heard about a plugin from a company called "PiXYZ-Software" that would automatically handle the process of taking any file that had come from any CAD program and turning it into a .FBX file that Unity could use!
After some manual processing, I managed to get through all the models I had in one day and I was pleasantly surprised by what the plugin in Unity could do! Topology was generally also pretty clean. Cool product(s) to use and would recommend to any who have CAD models sitting around on their hard drives!
I also took this opportunity to generate some hard-surface normal stamps to use in Substance Painter. I placed every model I had in one scene in Maya and began grabbing normal pass renders from the old Maya Software renderer with the help of a custom script that I had found and purchased online.
Most of the CAD file had not just come with one part but a hierarchy of other objects. I'll be able to take any model, swap some parts, and create any sort of mechanical normal texture I'd want.
It's a start at least!