I was able to do the user integration but was not able to embed the phpBB forum into the Drupal site as part of it like the way the coder explained in the module.
Also the topic in the Drupal website is not much helpful for anything you may want to do.
One last thing you should take into consideration is what if this guy stopped the updating or supporting for this module? are you able to do anything to let it work or you will screw your website or get under the risk for having an outdated software.
What I am about to do is to use phpBB with Drupal without integration, or to use Drupal for the whole website without any 3rd party and use the advanced forum module side by side with other modules like the following: