[durentis]

For the benefit of anyone else who may find themselves in a similar situation, by partner came upon an idea for a simple workaround to the above issue. Took me a bit to figure out how to implement it, but here you go.

vB is more than happy to manipulate thousands of forums with random passwords. It's the thousands of user groups each with custom permissions that seems to cripple it. All I had to do was link my own access group code into the top of forumdisplay.php and just before the first hook set a cookie with the relevant forum password if the user has access to it based on my criteria.

Essentially put this immediately after the // ### START MAIN SCRIPT ### block:

require('backend.classes');
$myClass= new backendClass();
if($myClass->hasAccess($foruminfo['forumid'])) {
set_bbarray_cookie('forumpwd', $foruminfo['forumid'], md5($vbulletin->userinfo['userid'] . $foruminfo['password']), 1);
}

Would have been nice to use vB's access groups, but this works very well and I never have to give out the passwords so it amounts to about the same without all of vB's caching overhead.