If your only goal is to eliminate any extra queries, you might be able to add your data to an exitsing table, or create a new table, then add it on to an existing query, depending on exactly what you're doing.
That's exactly what I need to do. Now I just need to figure out how to change all the existing code to work through the showthread_query hook.
Edit: nvm, I'm not sure that will work because it will there is are potentially multiple pieces of information for each user, which likely means I can't use that query.