I've added a new feature called "Related Threads" to the board. When you reply to a message, you can now choose to either reply in that thread, or start a new thread with your reply. Multiple threads will then be grouped together as part of a single topic. You can easily find other threads in that topic by clicking on the "Related Threads" expandable box below the message.

Despite my elite coding skills, it's possible that there are bugs in this new feature. Please let me know if you believe you've found one.