Warnings Can't Negate Permissions in XenForo
XenForo doesn't use a negative Warnings (Infractions) system for permissions like vBulletin does. Thus it is impossible to disallow permissions due to infractions under XenForo. In order to allow for this, a modification to VaultWiki's permissions system needs to be made so that, like XenForo, there is a "Never" variation of "No" that cannot be overridden. This would have the added benefit of making the permissions model more straightforward.