I can envision a lot of simulations that might benefit from allowing the researchers and experimenters to work in a VR environment, even without "hardlight" projections or something.
I mean, I keep building this robot, piece-by-piece, in a virtual space where I can assemble them, so I don't have to design every piece in a tool specifically for pieces, and that would the be the tool I use to not have to machine it myself in trial-and-error.