When setting up discounts, we usually need to set up the discount structure from the Customer perspective, rather than from the Product perspective.
So it would be great to have a Discounts tab in the Customer profile view, exactly the same as how it works in the Products profile view.
Then you'd be able to select products individually, or in batches via product categories/brands/tags/attributes, and build the discount structure for it.
Furthermore, I don't know of an effective way to view what deals a particular Customer has applicable to them at the moment. This would fix that.
Even better would be that the Discounts set up would sync between the Product profile and Customer profile, and therefore display in the Discounts tab on both.. maybe even in the Product Deals module inside Settings > Reference Books too.