How to make multiple variants of a texture quickly with "Send to substance?"

Hi there. I have run into this issue. I create for instance a 2x2 wall, create and apply a material to it after using “send to substance”, and then I want to make a second variant of that texture. So I make a second material, apply it to the mesh in UE4, and then “send the mesh to Substance”. Once in substance, I realize that in UE4 it is changing not only the new material I made, but also the one applied to it previously.

Obviously I’d like to use this “send to substance” feature so I don’t have to export/import all the textures and set up the material every time I make a change, I don’t know how I’m editing 2 materials at the same time.