That sums it up pretty nicely, I think. Not even talking about different HDR formats here 
Just a question from my side: If setting HDR output to enabled with a SDR TV connected, would there always be a HDR flag that the TV would then ignore? So, wouldn’t it be the better option to always leave HDR output on and let the equipment then show either HDR or SDR while ignoring the HDR flag (instead of dithering)?
And that leads me to the question: Is there any plan to have two options for us users in the settings menu: an option to enable/disable HDR output manually (and maybe an option to tweak dithering with some profiles) and an option to manually enable/disable 10-bit output (overriding any related EDID information with those two options) - the second option could be useful for those who have a SDR panel that supports 10-bit input?