Shoutout to the old timer who said my pruning cuts would rot the tree
He pointed at my flush cuts on a red maple in Salem and said 'son, you're cutting into the branch collar, that wound will never close right' and three years later every single one of those stubs is a hollow pocket, so now I want to know if any of you still see flush cutting taught anywhere.
Funny how the old guys handing out free advice at the job site are usually right and we just nod along and keep doing it our way. Flush cuts were the standard forever, taught in schools and passed down, and it took decades of dead trees for the pros to finally admit the collar cut was the way. You see the same thing in tons of trades, someone learns a method thirty years ago and nobody ever tells them it changed. The arborist world really did flip on this one, and yeah plenty of old books and old teachers still had it in there for way too long. Your maple is basically a three year science fair project that already gave you the answer.