Starting a new thread as suggested by @hpst
I have been having this led strain problems for quite sometime. The following combination seems to give a usable display (for me) on Lenovo laptops running Manjaro Linux KDE. I have done other modifications such as Xorg configurations, so this might be a cumulative effect, but this last modification gave significant improvement. So, this might of help to someone, even if they have other laptops or Linux distributions:
If you have discrete graphics, disable it and use only integrated, by selecting UMA only graphics in the BIOS. (This probably is not mandatory. Did this only to eliminate potential problems with hybrid graphics, non-intel drivers also doing modesetting etc.)
Pass the video option to the grub command line. For example: video=eDP1:1920x1080-16
Format is: dislpay:resolution-bpp
display value can be obtained by doing xrandr
The default bpp seems to be 32. 24 did not seem to reduce the strain. 16 does reduce the strain. Some monitors are truly 8-bpp, in which case this value could probably be 24. The test image at https://cdn.avsforum.com/d/de/525x525px-LL-defb4132_vbattach85246.gif at the site https://www.avsforum.com/forum/166-lcd-flat-panel-displays/874438-test-your-lcd-panel-s-dithering-technique-pictures-included.html seems to give some good guidance on this aspect
For testing this, you could press 'e' at the initial grub screen, add video=eDP1:1920x1080-16 in the arguments (typically after quiet).
For permanent, add video=eDP1:1920x1080-16 to GRUB_CMDLINE_LINUX_DEFAULT and do "update-grub" (or equivalent in your distribution).
Some pointers related to the video option:
From my limited understanding, it seems that Linux KMS is setting the bpp to 32 which causes dithering.
Please post your feedback, positive or otherwise.