(In reply to bmilreu from comment #68)
> try 0001-drm-amd-display-Add-fast-path-for-legacy-cursor-plan.patch

That one works, also with modesetting driver.

Regarding your question if modesetting driver is any beneficial: I'd say
generally not, as it doesn't offer every feature of the xf86 DDX driver.
But it can be sufficient in many cases, and I also just found a bug with xf86
driver + amdgpu.dc=1 causing stutter in mpv. So I'm lucky to have modesetting
as a fallback in the meantime.