Quantities coming soon, but categories first. We've set up a dedicated FAQ on the ShopBuilder highlighting what's been added and what is coming: What features will be added
We've also added a ShopBuilder wishlist in a separate area for customers to add new requests or like existing ones so that we get a sense of what we should prioritise next. There is already a post so please feel free to like that. Though I'm confident quantities will be one of the next features on the list.