RDM doesn't show any Retina resolution.
I tried to generate displayproductid-***.plist for my monitor using a script: codeclou.github.io/Display-Override-PropertyList-File-Parser-and-Generator-with-HiDPI-Support-For-Scaled-Resolutions/
But
Code Block ioreg -l | grep "DisplayProductID" ioreg -l | grep "DisplayVendorID"
returns nothing.
Also I tried this script: github.com/xzhih/one-key-hidpi - doesn't work, too.
Note that this folder cannot be modified even when SIP is disabled: /System/Library/Displays/Contents/Resources/Overrides/