Material param Customized UV disabled for Slate Brush?

Hi,

It seems like Slate doesnt take into account Customized UV when it is set directly on the material. It is fine when I connect my modifications to the UVs input of the TextureSampleParameter2d and then the TextureParameter is attached to the material by the EmmisiveColor param. Odd thing is that, the material gets drawn like it should when I use regular method from Canvas DrawMaterial(), but as for slate the texture is drawn modified only when UVs on the texture in fed with the computations.

Here is the way it does not work for Slate:

And here Slate draws it fine:

My concern is optimization for mobiles and as far as i know Customized UV allows to compute vertex shader alone. Can I somehow make it work for Slate Brush or WidgetBlueprint without using canvas methods to draw a material?