Texture scale on faces

Hello community. I have a last problem for my OpenCascade 3D viewer.

I have a shape (a rectangle) composed of two faces, one for the front face and one for the back face.
I managed my shape like this because I have to draw different materials on the each face and need to be able to select independently the front and the back face.

I apply textured materials (PBR) on each face using the XCAFDoc_VisMaterialTool class. Everything is OK for this point.
The problem is that now, I need to apply different textures scale for each material.

I only found the "SetTextureScaleUV" function on XCAFPrs_AISObject so I can apply texture scaling, but it always apply to the whole object and I couldn't find a way to apply it on each face independently.

Is there a tip I can use to achieve my goal ?

Thank you very much for your answer.