i still remember it from way back. is something like this planed somewhere in the future? 
I’m not sure but I think this is now VrayMetalball. You can use positive and negative particle systems along with a texture.
Is it not the same? I do remember VrayISO but not very well, so I can’t recall if had different functionality.
Yes, metaballs does do ISO surfaces, but the old vrayISO was great because you could just use geometry as a base and it had a viewport preview.
Would love that functionality to be back