Unfortunately I don’t have access to the project anymore, I’m sorry. But a bottleneck would depend on your hardware rather than the engine itself, that said, UE has very good scene controls similar to what you’d expect coming from CAD, like layering, individual object visibility, and grouping.
Best recommendation I can make is to give it a shot, even if you don’t have the CAD project ready, just batch-copy a ton of polylines and import them to the engine to begin getting an idea of your results.