This appears related (if I look closely enough during boot / periods of high CPU usage, I can see these artifacts on my hardware as well):
I actually remember seeing this “static” booting up the live image during installation, and I just brushed it off as new hardware running on an old Ubuntu kernel, figuring the OEM kernel would fix it (it didn’t). FWIW, I’ve tried resetting the display cable a few times with no changes.
I’ll try running the live image with Ubuntu for a bit, allowing the power saving features to take effect to see if I can reproduce the flicker there and compare to a live image of a distribution with a more recent kernel to see if I get the same issues.
My gut feeling is that this is software, hoping to pin it down before my board goes out of warranty.