I turned an annoying Xorg glitch into a shader 

That's interesting. I have a similar issue on my Linux system running Mint and Xorg. But for me the whole display blinks black xD I need to move the cursor or even better some windows (update many pixels) for it to stop flashing. Most often it happens after returning from sleep state but not always and sometimes just randomly during use. And as for you it doesn't happen on Windows, so I'd rule out hardware issues ¯\_(ツ)_/¯

Are you sure your GPU isn't dying lol?

12:50 what if it is gray #888?

Thanks, I hate it

occahional white flahes across the screen