I used to run a very successful XenForo forum (which I sold). However, if I may respectfully offer up a suggestion. Any thread created should be set by default to be auto followed by the thread author. I don't know IPB3 very well, but I suspect this option is available.
The only reason I'm mentioning this is that I had made a thread and a number of replies occurred, but I had no idea since I didn't receive notifications.
This means any new person would think the forum was way less active than it really is. Just an idea and certainly not trying to tell you all what to do, obviously do whatever you guys wish.
Thanks for having me,