Darn! I was afraid of that. I’ve been on a quest for many many months now looking for the software that makes those greyscale images. Thought maybe all along Fusion was the answer. That image you found has been prepared as a heightmap for 3D CNC relief carving.
I revert back to my most recent conclusions - software to do this doesn’t exist. It’s the hard way or no way I think. I’ll keep digging though. I will either master the hard way or find the software way. Somewhere.