The workaround does actually not work, therefore also the PR is wrong. I don't know what I was thinking of when constructing this stupid workaround.
Anyway the question now is if this behavior is intended.
1) If so that means one can refer to attributes of the element type in the WITH-clause. Then maybe we should create a note in the documenation about this?
2) If it isn't then it should be forbidden to refer to the attributes of the element type in the WITH-clause.

I don't think that 2) is an option since that would make certain queries impossible.
I'd say this matter is "resolved" as soon as documenation for it is added.