Optimization for thousands of draw calls in the CAD mesh data

Hello,
I would like to hear a side opinion on the optimization strategies. Having enormous CAD meshes in Unity with tens millions of vertices and 3-10k draw calls what would be your approach to optimize the draw call problem?
Setup would be mostly used for viewing and interacting like NVidia Holodeck. Let's say simplification of the model is done, I am still left with the draw call problem which is more heavy on the performance than vertices count. The problem lies In the wish to interact with each object (there are thousand of those, each screw separated) , combining the meshes is impossible then.
Would some custom culling method be effective? Like depth based culling methods? Or are there some known methods for dynamic batching with fast separation of the grouped parts? (Latest hardware is used 1080Ti or P6000 with the idea for setup to work in VR)
Thank you,
Karol

 

Atlasing/merging.

Culling won't help that much here.

Try Simplygon or SimpleLOD.