[HELP] Rigify to Unity in 2022

Hey, I’ve struggled for several days to figure out a problem and at this point I’m pretty desperate:

The company I work for purchased a pretty expensive 3D anatomical model that was fully rigged and created for Blender, but we ultimately need it for Unity. Originally the model was created for 2.8 and the rig can be posed with the Rigify addon, but any of my attempts to export that to Unity have failed. Ive tried exporting from several versions of Blender; tried Unity assets like “Rigify to Unity”; followed several guides, but all of this seems outdated and nothing works - the rig controllers in Unity are either completely disconnected from the mesh or, at best, extremely buggy.

Would be extremely thankful for any advice or guidance what would be a good way to go about getting a Rigify rig to properly import in Unity - hoping there is a working framework nowadays (or, at least, a workaround), because I really wouldnt have the time to re-rig all of it (and the fact that prior to this I had 0 experience in rigging/animation).