Am I right that you're saying that because of the nature of Dolby Vision, the colourist is best able to optimise the content within the limitations of the home display? Therefore, there should be no need to adjust the settings on the home display because the colourist should have optimised this taking account of the display characteristics?
Because each TV manufacturer is applying different HDR10 tone mapping principles (particularly for 4000-nit content), there is value from some control over tone mapping settings, to stop making things look too dark on an LG display, for example. However, I'd prefer to see things how the colourist intended it to look on that particular display. Are you saying that Dolby Vision will give us that?
According to the white paper from Dolby themselves - that is the intention. Of course its not 'perfect' and 100% exactly as the Colourist intends because of the 'limitations' of the display and the need to 'map' the content down to these TV's
The reason LG TV's look dark with HDR10 for example is because of the 'tone mapping' algorithm they apply. Using an OLED with 700nits Peak Brightness for example to illustrate 3 methods of HDR10 tone mapping
1) map the brightness accurately up to the limitations of the screen and then clip everything above that. This means that up to 700nits, all content is displayed at the correct brightness but everything above 700nits is 'clipped' losing all the detail. It does give a brighter APL overall but everything above 700nits is lost.
2) scale everything down so that something mastered at 1000nits is now at 700nits, something intended to be 100nits is now 60nits because everything is scaled. This keeps all the details in highlights but makes 'dark' areas/scenes appear much darker/dimmer and overall has a dimmer APL.
3) accurately map the brightness up to a certain point but scale down the highlights. This method keeps the details but often means you are compressing 250-1000 (or even 4000) down to just 250-700nits and can lack the impact in the highlights although does keep the detail in the highlights. Because content rarely hits 1000 (or 4000nits), the Highlights also never reach 700nits when scaled. 800nits for example may only hit 550nits and if the film never hits 1000, then the OLED never reaches 700nits.
What Dynamic Metadata can do is look at each scene and decide how best to map the content to the TV. It knows that the TV can only hit 700nits. In a scene that only peaks at 500nits, its better to use Method 1 and accurately map the brightness. In the next scene, it may peak at 2000nits but the bulk of the image is 250nits or less so it uses Method 3 but also compresses the highlights from 250 to 2000 (so the 2000nits hits 700nits). In the next scene, the peak is only 1000 and the bulk is 350nits, so it maps everything to 350nit properly and makes the 1000nit peak hit 700 and scales the highlights down from there.
LG seem to use Method 2 with HDR10. Whilst everything is detailed - including Highlights, it also means that the bulk of an image (often 85% or more) that is under 200nits is also scaled down and maybe only at 150nits or less.
The colourist may set 'rules' that determine the algorithm to use to ensure that content is displayed to the best of the screens ability. For example only scale the highlights that occupy 10-15% of the screen but keep 85-90% of the screen accurately mapped to the brightness level and always take the max peak brightness in the scene as the max level to scale to so the max highlight in the scene hits the maximum capability for example rather than tailor everything to a specific screen. That means a TV that hits 700nits will scale the highlights just as well as a TV that hits 1500nits and that at least 85% of the image is consistently delivered at the correct brightness so dark scenes are never too dark. It means you get more spectacular highlights too because they hit the maximum level more often too.