Can there be more couriers at the island, or have the three that are there return to the rift sooner? If someone wants to thin the veil, they can only deliver three magical items at a time, and then they have to sit there twiddling their thumbs to wait for the couriers to come back. So if the three items given shake the veil, any ragers around are going to be immediately alerted to the fact that someone is sitting around outside the nexus cabal guardian. For nexuns, this isn't really a much of a problem since they can just run inside and wait. But non-nexuns have to sit around in the open, waiting to be attacked. Additionally, while they're sitting around wait, the village can decide to get busy and start collecting items while their powers are still strong, and then slam the veil 10 times in rapid succession if they want, not giving magi a chance to compensate while their stuff still works properly.