Discount by Product Type

I’ve downloaded this, but now I’m rather stuck…

I have a store arranged by dog breeds (approx 100), one category per breed. In each category are a variety of products related to that breed. I want to be able to offer quantity based discounts, but by product type. So if I sell shirts, I would want a specific discount on the number of shirts of the same design, a different quantity discount on the number of keychains, one for hats, etc etc. All in all, 10 or so different item types. I do *not* want a discount by breed, but by the product type, globally.

The problem is I don’t see a way to do this by product type. Categories doesn’t work, as I don’t separate my items that way. Most of my products are variable (usually 16 variations or so). I can’t select “specific products” because I have over 6k products (not counting variations) in my store, and I also don’t want to have to manually add items to my discount structure every time I add new products (which is often).

Is this something that can be done with this plugin with the way my store is set up? I’ve been asked about quantity discounts and I’d like to implement it through my store instead of manually.