New command /wb portal <on/off>, which will allow you to disable WorldBorder's portal redirection method that is used to force portal targets to be inside your border. Requires new permission "worldborder.portal". This command has been added due to reported incompatibility with the Multiverse plugin somehow preventing that plugin from creating new portals. I see no way it should somehow be incompatible, particularly on WorldBorder's end which simply changes the target location of player Portal travel events, but there you go.
Release 1.7.1