Thanks, Just what I needed.
How did I miss that? Because:
No mention is made anywhere in the API about “dynamic components”.
“Behavior” says it covers settings available on the edit component definition dialog, but scale mask is not there (why not?). So way back when I read that topic I never connected “behavior” to dynamic components because most everything else that dynamic components do isn’t covered here because I have to remember it’s an extension.
Meanwhile “glue to” is called "snap to"
and "2D’ (not on the dialog) means the sames as “faces camera”.
What we have with this API is a huge haystack full of small needles.
And thankfully a forum patrolled by sages like Jim with bandaged fingers.