I would dispute your interpretation of broad powers to do it. I can assure you this is not a sneaky, surreptitious stealth way of doing tanker traffic, by having the minister regularly invoke special powers. This is very specifically focused on one situation, which is a very serious unexpected emergency situation that occurs somewhere along the coast on a one-time basis where there is a need for a larger amount of fuel for whatever reason.
In that case, the discretion exists with the minister to invoke that exception. However, we're not going to be talking about sneakily trying to develop tanker traffic on the north coast of British Columbia after putting in place a moratorium.