CAD data and real-time graphics data are not real friends. It’s a good piece of work to convert the many native CAD formats that have established themselves over the past decades into potential low-poly models without sacrificing quality. A really tricky opimation problem! Some top dogs have established themselves here, of which only Dassault Deltagen in the high-end range or the French challenger PiXYZ should be mentioned here. Unreal has its own solution in its baggage, which fortunately can be used free of charge even today: Datasmith.
Part of the Unreal Studio offering, Datasmith is designed to solve the specific challenges faced by people outside of the game industry who want to use the Unreal Engine for real-time rendering and visualizations — in industries including architecture, engineering, construction, manufacturing, live training, and more. But it also may be of interest to game developers who share similar problems in their asset pipelines.