The examples in the video are gorgeous! I'm anxious to try this technique.
I had the same thought that someone mentioned in the youtube comments, but wasn't answered ...
She inked the whole foil piece with Stazon, then stamped the tree with Versamark, sprinkled with embossing powder and heated. She mentioned the heating would dry the Stazon so it wouldn't mar your embossing folder ... but if the Stazon wasn't dry, wouldn't embossing powder stick all over it?
It will be interesting to see what happens. I understand you're wiping Versamark over the foil several times anyway, so precise heat embossing isn't really important, but it seems you wouldn't want it everywhere either.