Customized UVs in materials not working in iOS

Even if I don’t use customized UVs this way and instead modify TexCoords and plug that into the texture node input it doesn’t work.

Hello, I’m trying to parametrically scale UVs in a material.
I set “Num Customized UVs” to 1, and scale the TextCoord with parameters. It works fine on the editor but on iOS the texture doesn’t scale at all.
I’m using this technique to work around the need to have power-of-2 textures. I create a pow2 texture, but scale it so that the part of the texture that isn’t padded ends up perfectly matching on the mesh, the rest being discarded. It just doesn’t work on iOS. Any way around that?
Thanks.

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