You could still do a basic a/b extraction on the remaining bark, and you will see if you missed anything. With heat your chances of pulling the majority of alkaloids is higher is my understanding, but your not wasting material by any means. If it's not in your water then it's still in the bark-
At the center of this existence, it is everything and nothing, all of us and each of us and none of us. My light is now lit, and it cannot be extinguished.