The fundamental limitation of exporting a mesh to Blender/Unreal/Unity is that you don’t use all the density information that is in the CT. You can do much better! You can use Colorize Volume module to create an image that preserves all details of the CT but modulates color and overall opacity of structures based on the segmentation. This is just a much richer and more faithful representation of the original image data than any of the purely surface mesh based visualization approaches could ever achieve.
See some examples in these topics: