I noticed that Ditherig 2.0 is released, now called "Dithering Settings for Integrated Graphics". The description claims it can now disable dithering on integrated AMD graphics. Exciting if true.
freeware - henteko.co.jp! (kawamoto.no-ip.org)
Software to change the dithering configuration of Intel and AMD CPUs in notebooks to improve the image quality of the built-in display.
Spatial, Spatio-Temporal (a.k.a. FRC), and Temporal dithering are available on supported devices.
Disabling dithering enabled by default can be done to get the best quality for 8 bits or higher displays or to mitigate eye strain.
This requires Windows XP or later.
This requires Intel 6th generation graphics or later (e.g. Intel HD Graphics 3000, including Sandy Bridge, Ivy Bridge, Haswell, Silvermont, Broadwell, Airmont, Skylake, Kaby Lake, Goldmont, Coffee Lake, Goldmont Plus, Amber Lake, Whiskey Lake, Ice Lake, Comet Lake, Lakefield, Tremont and Rocket Lake generations) or AMD GCN 5th generation graphics or later (e.g. AMD Radeon Vega 11 Graphics, including Raven Ridge, Picasso, Renoir and Cezanne generations).
I have checked behavior with the combinaion of Intel UHD Graphics 620 and NVIDIA GeForce MX150, Intel HD Graphics 515, Intel Iris Pro Graphics 5200, Intel HD Graphics 4000 and AMD Radeon Vega 8 Graphics.