Congrats on the new mill! Due to many variables, it is very hard to exactly pinpoint what your efficiency will be for any given mash. We can come close, but even when you hit your your number on the head, we still have to boil it. We can again, thru repetition dial in our boil losses pretty well, but there are still plenty of variables. What this is leading up to is a reminder that a last gravity reading before you cool your wort to pitch temps, will allow you to tweak your numbers. Too low, add some DME. Too strong, water is your friend. Hope this might help. take some muscle from your Super Kolsch .