Thread:Help talk:Concepts/Inverse referencing for user pages in Concepts

I'm trying to generate a list of contributors to a particular effort that I can leverage for a type-ahead field of a form. I thought the best route to go would be to create a Concept. I'm runming SMW 2.1 and have Extra Special Properties 1.3.1, so I am trying a Concept page that looks something like this:

With "FOO Property" being a property present on all the pages within my effort. I have gotten this inverse property method to work on Concepts that do not reference user pages, but for some reason, when I save the concept the query shown on the Concept page reverts to:

without the inverse - and I receive no results. This same inverse query works fine on the Special:Ask page, so I am curious if this is a limitation of Concepts?