I've been looking at this on a MBP 2020 (13 inch) - the flickering is unbearable, and I want a fix for it. I tried updating MacOS but it did not work. Some report it as flexgate but that makes no sense when it appears the flickering of the backlight stops temporarily when the mouse cursor moves on screen. What I have noticed, and wanted to report on the off-chance it helps Apple figure out a fix for this issue, is that when I play videos on youtube or even via the opening "trackpad" settings (which also play videos to demonstrate the gesture controls) is that the flickering stops completely. Opening the mouse menu to setup a bluetooth mouse starts a spinning animation that appears to override whatever it is that is causing the flickering and stops it. If others can comment whether they're seeing the same results, perhaps it helps apple narrow down the cause of the bug causing this... its definitely software related my end rather than "flexgate".