[NickF]

Does the Raspberry Pi 4 and 5 both support  HDR10+ Videoplayback with Kodi/LibreElec ?
And what about DolbyVision at the Raspberry Pi 4 and 5 ?

[popcornmix]

Pi4 and Pi5 support static HDR (e.g. HDR10).

No per-frame (dynamic) HDR (so no to HDR10+/dolbyvision).