I may not be looking in the right place.
Try a mustard sauce. At it's most simple, it's mustard, brown sugar or molasses and cider vinegar. You can add whatever ingredients you want, like garlic, onion etc... For rubs, just salt, sugar, granulated onion and garlic and a little cumin makes a nice one. Cinnamon, clove and ginger can be added in small amounts to up the earthiness. Plain old salt and pepper works pretty well as a rub too.
I would make this per 2 rack of ribs:
2 bottle of Guinness .
2 cup of brown sugar.
reduce down to a thick syrup.
add in stuff you like.
maybe a tsp of EVO. some butter,
some vinegar or molasses, or both depends if you want sweet,tangy or a balance.
then add some spices for the flavor profile you like.
simmer for 20 mins
for a rub:
coffee grounds(or some other exotic for complexity)