Alright, here's some more comb pictures. 2 things are making this diagnosis difficult. #1, There is definitely powdered sugar on some of these frames. #2, the robbing bees opened the honey cells really messy, and there are crumbs of wax all over the comb as well. This is making it very hard to ID what is sugar or comb bits, and what is mite frass.
Exhibit A: For reference, here is a picture of a section with powdered sugar, and a picture of the ripped open honey cells, just so you can see what these things look like on my camera.
Not all the pictures will fit on 1 post, so just hold your thoughts for a minute while I post the rest.