Technically speaking if you're using your RO water then you're using water from your cold water supply so the RO unit will continue to make more water and if the waste is plugged into the cold water supply the filter will be forced to use waste water for intake unless you happen to be using another source for tap water at the same time which isn't always likely. Obviously not the greatest solution to the problem of waste water but at the end of the day it's still the most efficient system available. This is why a new system would be very innovative and honestly if I was making it I wouldn't say a word until I had a patent in place and even then wouldn't be targeting the smallest possible market for the product. Hence, I'll believe when I see it
In the mean time if the discussion is going to continue on the bases of zero waste RO we should move the discussion out of this vendors thread. I'd like to talk more about it as well and see if we can't rig up a DIY plug-in that can be adapted to all existing standard RO units.