I am currently writing this and streaming 4k streaming on Netflix on my 4k Vizio - don't think it has Dolby vision or HDR10, but it is handling this with no issue, connected via BT to a Harmon Kardon Speaker - no skipping or stuttering.
RAM is at 8GB, CPU is 95% idle, again barely above Idle. But I can't confirm the HDR10 question.
GPU monitor showing maybe 20% usage.