Substance customized sbsar location?

I wish to use Substance materials for part of my iOS workflow - mostly to make "programmer art" that doesn't suck quite so badly :) I really only want to get at the baked texture + normals so I can tweak it in Photoshop with overlays or whatnot.

I would like to customize the free "concrete_049.sbsar" so I select the "Add Substance from prototype" button and rename that copy to "MyConcrete" and I tweak it to my liking. I don't see a way to save the texture from within Unity. Can I do it in Unity?

As a fallback(?) - the Substance Player does have this ability, but I don't know where the MyConcrete "copy" is saved. Substance Player (MacOS version) doesn't show me multiple versions within the sbsar file so it doesn't seem that it in a resource fork or whatnot in there :) Do I just have to copy the .sbsar myself to get it into Substance Player? Seems awkward. Any tips appreciated!