RedViewer has been available for a while now; it can be quite good, I suppose, although last time I checked it out, with more complicated scenes it tended to drift away from real-time as well.
Yes it’sa pity for redviewer, at the time I met the development team (3 persons in Paris) and I asked a Vray compatibility, especially for Vraylight and reflection.
It was very useful to place plane of reflection.
I don’t understand why it don’t sell the product anymore separately.