Correct, the concept is not the same. It’s not hard to figure out as you have, so I’m thankful that ArchiCAD has implemented it correctly. For what its worth, the BlenderBIM Add-on has also implemented material properties for a while now. All I’m saying is that the documentation currently doesn’t talk about how to do it, so one has to make assumptions 
It’s an easy documentation fix.
Whether or not materials should become rooted, is a separate discussion You’re right that if you solve the rooted issue, you can simultaneously solve this issue too.