blender 2.83 has vr support since its latest release, combined with the evee realtime renderer you could acchieve something like you intend to do. I doubt there is support for multiple users, but maybe that at least an option to look at. You can also try to implement a CAD core into unreal, i worked on such a project for my bachelors thesis and it worked surprisingly well. We used siemens NX for that, but it could probably also work with other cores.