All I can say is: sounds interesting! Couldn't you do a tiered test with rosewater at bottling? I.e., put one drop in the first bottle, two drops in the second bottle, three drops in the third, etc., and label them accordingly? That way you could do a somewhat controlled test to see if the flavors go well together. That would give you a target if you decide to "dry hop" a larger batch with rosebuds.