Screen randomly flickering blank for a second on Optimus - Razer Blade Pro 17

(Razer Blade Pro 17 2020 4k 120Hz 2080 Super Max-Q (RZ09-0329x))

In Optimus mode, the screen will randomly flicker black, as if it was turning off and on for a second. Sometimes, it does not occur for a few days and sometimes, it is every few minutes. This problem is generally traced back to the Intel Graphics drivers and the Nvidia Optimus switching. It never occurs in dedicated GPU mode. Going in and out of sleep or restarting sometimes helps.

It does not seems to be the same thing as the Nvidia black screen bug that is frequently reported when using Geforce drivers after 452.06, where the screen stays black and a force reboot to Optimus is needed.

I've tried every known workaround:
- Installing either some very old or the latest Intel Graphics drivers (latest being 27.20.100.8935)
- Same thing for the Nvidia drivers (latest 457.30 Game Ready DCH)
- Seen on Windows 10 2004 and still present in latest 20H2
- Bios 1.04
- Played with the power options in Intel Graphics Control Panel / Command Center (self refresh, power savings, etc.)
- Played with the "Preferred graphics processor" in Nvidia Control Panel
- Played with Windows power management options (power mode, Intel Graphics power plan)
- Played with random settings in Synapse
- Same symptoms plugged in or not

Here is another recent post about it : /razer-blade-pro-17-4k-2080-maxq-screen-goes-blank-randomly-for-1-second.64562/
This old thread may concern this bug but also has reports on the other but related Nvidia black screen bug : /razor-blade-15-periodical-black-screen.50472/

Help? Is it widespread, tracked anywhere?