Btw, did you ever get to actually see the effect of your HDR10+ metadata on your display? 

I prepared 4 versions of the same clip, namely

• PQ10, i.e. PQ transfer characteristics and BT.2020 color space (no metadata at all!)
• HDR10, namely (1) + static HDR10 metadata (mastering display color primaries + min and max luminance + MaxCLL + MaxFALL)
• HDR10+ Profile A, namely (2) + dynamic metadata consisting of luminance distribution parameters
• HDR10+ Profile B, namely (3) + dynamic metadata consisting of Bezier curve parameters

The clip included some very bright scenes, some more balanced scenes, as well as some very dark scenes with a few bright spots.

To assess the four versions of the clip, I photographed the TV screen from a long distance in a dark room, of course taking Raw pictures and baking them with exactly the same (somewhat neutral) settings in ACR.

The results:

• version 1 is slightly darker in all cases (this somewhat surprised me as I expected on the contrary that no metadata could lead to oversaturated / clipped highlights)
• versions 3 and 4 look apparently identical (no surprise), but they seem to roll highlights (as well as shadows) slightly differently from 2, in a non-trivial way (in most, but not all cases, increasing contrast slightly)

So yes, in the end I could find some differences with my TV -- but very subtle, in many cases visible more by comparing the sample pictures histogram rather than really perceivable with the naked eye.

Sergio