Great Addon.
As the header suggests, a friend of mine and myself feel it could really benefit from a scaling UI option. There is often a lot of data/information to see and scaling could help users reduce the scale to a size they can see it all.

Could you explain a bit more on your idea? Right now all I can think is resizing the window is possible, unless you mean changing the font size and everything.

Of course. My initial idea is along the same ideas as the wow UI (System>Advanced> UI Scale) or addons such as Recount, where you can reduce the size of everything to do with the on screen window (for ATT this would be the icons and the text, I would presume it could include the window frame too), usually it's a slider bar that is set at 1.0 (the normal size) and the range on the slider determines the size. This could be for example 0.5 (half the normal size) or 1.5 (an increase of size by 50%).
For my selfish purposes what I would like to have happen is for me to move the ATT window to the side of my screen, set it to about 3 inches by 10 inches in size, and be able to see everything clearly in the window. At the moment all I see is a lot of "0 / 0 (0%)" text overlapping the item/category text. By reducing the size I could see and read clearly everything.

Added the ability to apply scaling to the Main and Mini Lists from within the ATT Interface settings. It should be available with the next release.