Many years ago, I used to use the Blitz3D game engine to create game prototypes.
It was based on a DirectX 7.0 sub-system, which could not handle shaders, but it could do dynamic cube maps for reflective surfaces.
I have tracked down an old example at:
Can the blender game engine do this?
If not, why?
This was an acheivable feature in 2001 using a very old version of DirectX.
If my memory serves me well, the programming language had one function called ‘SetCubMap’ and you could also specify an alpha value so that the surface was semi-transparent.
This is the kind of feature Blender needs to take it to the next level.