If I were a billionaire, I'd finance a project where this kind of technology is used on witnesses of historical events (WWII battles, marching with MLK, lost rock concerts, etc). Ask them to visualize the event, and record their visualizations. Obviously any individual witness would be unreliable, but data recorded from multiple witnesses could be valuable.

Time is running out. I don't know how many WWII veterans will still be alive by the time I'm a billionaire.