[noggin]

It can be one option. Although, not easy to find a reasonable priced splitter that supports HDR+ and Dolby Vision.
I am fine with optical if that would work.

I’m using one of these to do exactly what you want. Does DV and HDR+ perfectly fine.

This is really promising!
So I can have full everything for N2 to TV (like it was connected directly) and on Hdmi2 from splitter to AVR and enjoy DTS, TrueHD, DD+ etc. Sound really great.

Is HDMI-CEC (passtrough) also working?

And the harder part will be to get one in EU (although I see it is available on Amazon UK).

That's the device I bought on Amazon UK.  When I get a chance I'll check CEC.

Being able to program the device over USB can be very useful.