Off-topic :- D
The "ghetto" (nothing ghetto when it's done inside Megascan box) setup can give you actually better coverage, nothing stops you from using stereo on 1x1m... the Megascan is 50x50 inside 100x100cm box. That's a lot better than X-Rite or Vray's scanner.
Properly calibrated with Macbeth chart the Albedo should be very close (but not on their extremes, the blacks and white are rather arbitrarily calibrated) and you will get same quality of normal map which you can turn into height map.
That's were similarities end. 'Basic' stereo can't capture metallics or other pure specular materials, actually they can't even capture wood properly due to anisotropy, there is a reason you don't see any on Megascan yet...
This scanner gives you identical copy of real-material, 1:1, 99.5perc if you use the resulting BRDF and not just set of maps. For Car or Furniture industry, you can be absolutely sure you are getting true look. That's pretty cool stuff.