[Disasterpiece]

I'll see what I can do.

Problem is that the vbulletin registration script itself is very isolated and hard to modify without modifying the vb core files which is an absolute no-go.
The way the steam authentication works, is by using its own login script (login2.php) and creating a session via the vbulletin API by itself.
There's no way to completely alter the core vbulletin login script, that's why the mod can only function as an extension instead of a replacement.

However, it might be possible to work something out with usergroups being assigned on registration, I'll see to it as soon as I get some time.