Two sides custm stencil? - different stencil on each side?

Is there any way currently to assign a second value to the stencil depth of a mesh or a per-texture stencil value?

I’m trying to mask something and the plane that masks is double-sided, but one side should mask out and be invisible while the other side should not (unless the item is actually though the plane).

I was thinking this would be pretty simple to do if I could just assign a second material or a second stencil to the mesh reverse side.

Adding another mesh here would cause significant performance loss, so I’m not really keen on doubling up the actual mesh. the material has some 1849 instructions (transparent shader)… which I should probably already optimize a bit.