The syrup won't impart much flavor if at all in my experience. I recently made a batch of apple-peach using canned peaches. I put the peaches in a zip bag, smashed them up, and added the peaches and the syrup. I do suggest you add pectin enzyme if adding fruit; it helps to pull all the juice out of the fruit, and clear the cider when finished. I added 2 cans to 1 gallon of cider, and it tasted good, but the peach flavor wasn't really strong. I freeze concentrated it and then it tasted like peaches.