I implemented a shield mesh with two materials, one with 1:1 UVs and the other with 1:2 UVs. It works fine in the editor and within the Custom Battle menu, it does not work in battle.
What seems to happen, when both materials are present on the mesh, the 1:2 UVs stops using its material and starts to use the material of the 1:1 UV, but only in battle.