Steve, I am also having dimensioning issues. I now have a project where it is impossible to create a dimension chain through 4 walls. 2 of the walls always drop the dimensions. So I can dimension any 2 walls but not more. This happened to existing dimension strings so now I have to go through and check all my dimensions and discovered that several of them are no longer attached to any element but are just static dimensions. This could become an error that can cost me a lot of money and not just lost productivity.
At this point ArchiCAD needs to issue an official downgrade from 4011 for those not using El Capitan (with it's own pile of bugs) or Windows 10 so that we can be productive until they can do proper quality control on the next update.
For the labels the one thing I discovered is that the label behaves differently depending on whether you select it by the body or the leader. Once I trained myself for that difference I now am warming to the new labels.
Mac OS12.6 AC26 USA Silicon
M1 Macbook Pro