https://bugs.freedesktop.org/show_bug.cgi?id=108917
--- Comment #3 from tempel.julian@gmail.com --- (In reply to Alex Deucher from comment #2)
Possibly the same issue as bug 106175.
Do you suspect the mouse cursor issue? That's not the case here: The gamma adjustment stutter also occurs without vsync or any other fullscreen vsync application running.
I will give a Wayland session a try this evening. Wouldn't be surprised if this issue is completely unrelated to Xorg specific things.