Reduced resources setting was used to disable minimize effect and
to show wireframe when moving or resizing windows.

Minimize effect still can be disabled by using enable-animations
setting from org.gnome.desktop.interface schema. And if you are
really trying to reduce resource usage you probably already have
animations disabled.

Wireframe mode has not been updated/fixed to work with CSD windows
and/or to exclude shadow/resize area from SSD windows. Also quickly
testing with and without compositor wireframe sometimes leaves
parts of frame on screen.

Considering that there has not been any bug report about broken
wireframe mode I think it is time to remove it instead of wasting
time trying to fix something that nobody is using.