Upon further investigation, we've concluded that unfortunately this is not something that we can fix, apologies for the inconvenience.
Certain devices do not accept texture fetches in the vertex function with GLES 2.0, which is confirmed in description for the Render Target 3.0 in
Unity's Shader Compilation Target Levels, which states: "Might not be fully supported by some OpenGL ES 2.0 devices, depending on driver extensions present and features used."
Please don't hesitate to get back in touch if you have any further questions, thanks!