Add "class" field to Product Add-ons to apply CSS class
It would be highly useful to be able to add a product add-on class to each product add-on, which could then be echoed on the front end. This would be greatly useful in theming, as it would allow add-ons that are of the same type to be visually grouped together, particularly when the number of add-ons gets pretty long, as with a highly customizable product.
Even code to add to my functions file, which doesn't affect the core, would suffice. There is code available to accomplish this, but it requires editing the core.