Dorian has definitely weakened since his run back to major status last night. However, I'd also point out that in the past couple of hours he has re-fired a number of cold tops and started to wrap them around his inner core, and his structure looks better than it did 6-8 hours ago.
ADT shows that Dorian has probably stopped weakening for right now. In fact, he may be showing some very mild strengthening. Dorian is starting to have a very long history of doing this. I don't expect significant changes, but I could Dorian's pressure stabilize or drop 2-3mb. In the grand scheme of things, it simply allows him to continue to pile up the surge as you mentioned, and his fluctuations in strength are simply allowing him to grow larger and thus far avoid further truly significant weakening.
He is one of the more intriguing Hurricanes I've had the pleasure of watching.