Yeah, it seems to be. I'm only inferring based on how it works in Shoes3. I'm wondering if my approach for figuring out how stuff should work is accurate:

1) Check the Shoes3 manual. Get stuff to work as described there.
2) Try running the failing sample in Shoes3, if it runs, and the code uses undocumented features, then try to guess what the feature is based on what happens in Shoes3 and implement it that way.

It occurs to me then, should I be adding documentation for a feature like this as well as specs?