He's in good hands with Simon, who has surround mixing credentials dating back to the early '70s, which include the Gong quad mixes, etc. Hopefully he'll get a chance to do a proper ground-up discrete remix of one of Rick's albums at some point.
I think it goes without saying, but even in light of the palpable disappointment here that these first two projects have had upmixes as the source of their 5.1 tracks, we do appreciate your transparency on the issue, and that you've taken the time to interact with people here on Rick's behalf. I hope it's been rewarding for you at least as much to show that there is a genuine and strong interest amongst surround enthusiasts for real discrete remixes from his back catalogue.
I do recall reading somewhere that the discrete master tape for an unreleased quad mix of one of Rick's post-Arthur albums (White Rock maybe?) was located during the vault searches for the deluxe editions of Six Wives, Journey and Arthur albums. If that's something you could put on your radar to release, I think you'd find a lot of receptive buyers here.
Were the multitracks for Return to the Center of the Earth destroyed in the 2008 UMG vault fire?