I can do some testing on a SONY screen on which I guess I can disable DV. On my Formovie Theater projector I think I can’t disable DV to make it HDR-only however.
I have a HDfury Vertex2 and ugoos am6b+ so I’ll be glad to help and participate in this matter, but not before monday 20th as I have big dutties before 
. Thanks a lot for what you do. It’s cool to “jailbreak” the DV ecosystem a little bit more …
(and I’m probably in a different timezone as you, I’m in europe)
(… and I also have a PC monitor which is HDR-only compatible so I can indeed reproduce the real use case)