Well I do enjoy HDR10 thats for sure but having the extra touch would be great. HDR10+ well first that has to come especially for a bit older displays and then we need content for it. Wont happen before well maybe Q3-Q4 2018. So first lets concentrate on DV.
And regarding minimal differences you might be right ofc. But some movies look almost the same on Bluray vs. UHD Bluray due to 2k mastering anyway. Also minimal differences sometimes. But still we watch the big stuff if we can dont we