HDR10+ backwards to HDR10

[SlashX]

Like I wrote before: max cll and fall are missing there.

From what I read, I see that if in the source of the video maxcll is not prezent, better then put the wrong value, let it be 0 and use: 
--hdr10
Along with:
--hdr10-opt

It seams to be a better option for the video, benwaggoner said this:
https://forum.doom9.org/showthread.php?p...ost1906154

Maximum Content Light Level : xxxx cd/m2
Maximum Frame-Average Light Level : xxxx cd/m2

My video don't have those value in the info: So is better to let it be 0.

And that is where you go wrong.
VBV, profiles and level are not about the best for the content but for playback compatibility.
You need to select VBV, profiles and level such that:
a. they allow your content
b. are supported by your playback device.
read:
https://en.wikipedia.org/wiki/High_Effic...g#Profiles
https://en.wikipedia.org/wiki/High_Effic...and_levels

I readed all of that and also:
https://x265.readthedocs.io/en/master/cl...level-tier

It seams that x265 can determinate the encoding level based on the resolution of the video, framerate.
So the level on my video was:

Main 10@L5@Main

After encoded on auto-detection it got:

Main 10@L4@Main

And if I look on the tabel from:
https://en.wikipedia.org/wiki/High_Effic...and_levels
I see that my video with FullHD resolution and 30 framerate it fits on level 4 the same level that has been chosen by the x265.
Or maybe HDR10+ has another standard, a specific level only for HDR10, but I don't have information abaout that...

If you select a specific level Hybrid will automatically set the default vbv restrictions for that level.

After the first encode and seeing that my video fit in level 4, I can chose level 4 and Hybrid will do the rest, setting vbv for that level.
So my question is, should I use vbv or not? What is the benefit in using it or not?
I see that is a must for the internet content, it helps in streaming.

Thanks!