A real developer can add much but this is a configuration path similar to the Windows Registry that hangs on in MATE because of its GNOME legacy.
For example, Pluma settings reside here and can be manipulated with the gsettings command (GNOME-Settings I think). I used this here.
The old GNOME gconf-editor was renamed dconf-editor in MATE. I expected mconf… never figured that one out. 