Not sure if this is a bug or expected behaviour but I am using the solidify modifier with zero thickness and "Fill rim" checked off, so I can make the mesh appear "double sided" for a game.
I set the faces that I want to be double sided into their own vertex group and then selected the vertex group on the solidify modifier. It doesn't seem to do anything, I have "Backface culling" turned on and I was expecting the faces that weren't in the vertex group to be invisible, but the solidify modifier is still affecting them.
I noticed if I set some thickness on the modifier then it will only thicken the faces in the vertex group, but the other faces will still be there but just not thickened
(this is the result I get)
(this is done manually and what I want/expected..)