Did you try reducing down the blueberry juice? If it’s a savory flavor like you say, I’d be interested to know what properties it might have as a sauce.
More specifically, I’m curious how it’d be in three ways: one test group cooked down on its own with no additives, a second one simply used to deglaze a fond and made into a pan sauce that way, and then a third made into the same pan sauce, but then mounted with butter.
Hah, who knows? Maybe you could make a roux and try it as a gravy. Oh, or maybe, if you season it right, you could make it into like a sweet/savory/spicy chicken wing sauce?