Stop Using SwitchResX! Try THIS Instead
I was having trouble with both switchresx and displayconfigx, and then i followed your instructions, and now i am displaying my mac mini desktop perfectly framed in. Then, if you want to use single external display mode,. Develop your resolution as scaled in switchresx. To return to your default resolution try resetting your mac's pram and nvram. For more help with it, please contact.
I think you can turn off dithering with switchresx. You can choose 8bit instead of 10bit at the display/resolution settings in the menubar. I believe that should disable dithering (of course. Navigate to system preferences displays display. Need a keyboard shortcut to start or quit switchresx? Or shall the software start automatically, when you log into your account? This is the place to tick the appropriate boxes.