It took a few weeks, but it looks like the game has been indexed properly now. Support did get back to me, but it sounded like the indexing happened automatically and I just needed to wait for a while. I do have another demo that still hasn't been indexed in over a year, but I may not have completed all the steps for getting that game indexed and the full version is available on Steam anyway.
I'm leaving this thread here in case it is informative for me or other developers in the future.