I use a BeeLink S905X box with CE 9.2.1 (old kernel) and an Odroid N2
with latest nightly 20191227 (NEW kernel).
My TV does not support HDR, so I use the HDR2SDR
function of CE with setting to auto when playing 4K/BT.2020 content.
In my opinion HDR2SDR works much better on my old S905X-box. Colors are
not washed out, but pretty good and strong (but not too oversaturated).
On N2 the picture is too dark and there are sometimes heavy artifacts
(see my post Artifacts with HDR2SDR function)
The artifacts are vanished when HDR2SDR is disabled.
Concerning the too dark picture on N2 I have to use another TV-setting/profile and tune up
the backlight and contrast to maximum. The picture is better then but not as good
as with the S905X-box. With S905X the picture is more vivid and there are no artifacts with S905X.
This behaviour on N2 is exactly the same in the NEW kernel and in the old one also (with 9.2.1).
So it has nothing to do with the kernel-switch.
@anon88919003 mentioned the tonemapping is burried deeply in the kernel, so the CE devs cannot help.
So who can manage to change the tonemapping in the N2-kernel?
Can you give me a link to file a request? I don’t know how to start with this…
If logs or more infos are required, please ask me.