phpBB is a huge template that consists of more than a hundred of smaller templates and even more variables; a theme goes on top of the default template and overrides everything; extensions override something yet again, so we end up with a thousand of the unknowns and their dependencies.
Normally you don't touch it if you don't know what you're doing and this is why it may not be an option to "simply" add something if it's not a default feature and you don't understand all the dependencies, even if you can pinpoint it on your screen, where you would like to have it.
There's a learning curve to everything and no, I never learned phpBB and I'm not even a fan of it, so normally I wouldn't have answers straight away, but I would be willing to look into it, especially if it's driven by something positive.
In any case, it takes time.
