[4.25.2] Why are UserInterface Materials Drawn behind Surface Materials? and whats the difference?

I noticed while making my selection system, that materials that have a ‘Material Domain’ set to UserInterface but are placed in the world( rather than a UI widget ) are drawn behind objects that have a material with a ‘Material Domain’ set to Surface.

The issue is easily enough resolved by just using Surface to ensure my selection rings are displayed properly, but it left me wondering what, if any, intended use is there to using a ‘Material Domain’ set to UserInterface on world objects? I had initially assumed it was to ensure the object was drawn in front of the other world objects, but clearly that is not the case?
(I also tried Translucency Priority, but that didn’t work)