Going out with the new board today.
I still think the board is bad. Because regardless, even if there is some mechanical issue, you should still see some effect in the adjustments, but there was none at all. Even going to extremes, close adjustments could not keep the door from slamming the strike. The only close adjustment that had any effect at all was the overall close speed. But if that was turned down low enough to reduce the slam, then the close speed was at a snails' pace, and not acceptable. It shouldn't be this way. The close slowdown distance should have at least SOME kind of effect on the close, even if there is a concurrent mechanical problem. So the evidence still points to the board, although there might needs be additional mechanical work to be done.