Fake Member Total - Some people do a lot of active pruning of their member database, so by keeping things tidy we suffer from low member counts... In Classic we had the ability to have a "fake" member total which just took the last uid from the forums and that was your total...
Well it's not that easy to track in threads, but you can tell it to increase your member count by X ammount of users...
Open your cache_builders/forum_stats.php, replace this:
$smarty->assign("users",$users);
With this:
$smarty->assign("users",$users+XXXX);
Where XXXX is the number you want to increase the total by (no comma's), then clear your cache.
Now the forum stats will show your actual total PLUS the offset you typed in