One thing is clear from the latest HDR test build release notes and bug that appeared....the Envy IS running madvr...at least, a code path within it. Because the release notes mention this and the bug he had to fix was because of some Envy code. But, remember that what they're using in Envy is not off the shelf nVidia cards. Who knows what else is under the covers of that thing.
Nonetheless, I am quite happy I bought an RTX card. Even if the features don't 1:1 match the Envy in terms of new algorithms, I've got about 7.9 TFLOPS to play with on my card, so, right in the middle of the base and the pro. I'm very excited for the future of madvr!