Ok, so as promised I've tried to emulate a Dolby Vision Cinema curve.
I've set a target peak white of 106nits (that's peakY in Dolby Vision Cinema).
This is an approximation as I have no idea of the actual targets of DV Cinema, given that it's a different grade mastered to 48nits reference white 106nits (31fL for those still in the 20th century) peakY.
But using our content mastered up to 4000nits with ref white around 100nits, we can try to emulate it. It should work better for those with a dedicated room and no ambient light. Others might find it dull comoared to targeting a higher peakY in high lamp. I still have to compare the different options (DV emulation at 106nits, low lamp iris open at 140nits and max bright high lamp iris open at 200nits).
I attach a screenshot of the parameters in Arve's tool that should work very well for anyone able to set their peakY to 106nits. If you're a bit above or a bit below, it shouldn't really matter. The curve should work fine for 100-120nits peakY. However, you should check your black brightness parameter. 0.0165 is for my setup, to resolve down to 81 (illegal curve). You might need more or less that. The curve resolves up to 4000nits, so it's a universal curve.
The advantage for me is that I go from iris fully open (which gave me around 45000:1 native on/off and 140nits peakY) to iris at -6 which gives me around 60000:1 and 106nits peakY, so a lower native black floor and higher native contrast, as well as less DI artifacts.
The downside is a small loss of ANSI contrast, but that wasn't too visible in the quick tests I've done, and a loss of dynamic contrast (from 360000:1 to 230000:1), as with the DI the black floor is the same, only the white value changes, and it's lower in DV emulation mode, therefore less dynamic contrast in this mode.
I attach screenshots showing the contrast values, all taken with the DI off to show native on/off.
I have this saved in a DV Cinema user preset, and my former preset save into my HDR BT2020 user preset so I can easily switch between the two, each custom curve / iris setting is selected automatically. Both use low lamp.
So if you want to try this curve, ideally use the wip branch and copy the parameters in the first screenshot, except bb that you should adjust on your unit displaying the black clipping pattern and resolving down to level 81 (77 and below not flashing).
If you don't have the wip branch, then here are the parameters:
max brightness: 650nits
ref white: 100
hard clip: 4000nits
soft clip start: 275nits
soft end slope: 0.75
soft clip curve type: 0
soft clip gamma: 1
You can set the black point to resolve down to 81 using the brightness control in the player, even if it's not the best way to do so (best is use the wip branch and use bb to adjust the curve itself).
So if we all set peakY to 106nits and use this curve, we should all see roughly the same thing, taking aside on/off and ANSI contrast differences due to lamp and iris settings variation.
Please try it out and provide some feedback. I haven't done much checking because I need to re-run an autocal, but it looked pretty good here.
If everyone likes it, it could be a truly universal curve: one valid for all titles and for all setups (able to reach 106nits peakY or close). The good thing about this approach is that we simply have to set peakY to 106nits, set bb to resolve down to level 81, and off we go. There is no need for a different curve for each setup, and to mess with the parameters to adjust to your needs, but it's not necessarily the curve that would give the best results. It's an easy one-size-fits-all, it's not custom-made
I attach an untested low-res version for those who are still not using Arve's tool, so they can import it with the JVC Autocal software. This version doesn't use a bb parameter to make sure that I'm not raising black on your PJ, so you will have to set the black point manually, preferably resolving down to 81, not 68.