The shading rate for an item is the higher of the rate set on the item and the rate set in the Render Settings.

If you need a small shading rate value, you therefore must adjust both the value in the Render Settings and the value on any body parts or props that need a lower shading rate.

I think somebody did do a script to set everything in the scene to a shading rate of 0, allowing the Render Settings value to determine the shading rate.