A Pacific without the treaty fortification clause

How much difference would removing the treaty ban on new Pacific fortifications have made?

It could have produced much stronger island bases, especially for Japan, making the route to the Philippines harder to reopen.

Without the fortification restriction, the United States, Japan, and Britain could all have tried to offset treaty tonnage through stronger Pacific bases. Japan's former German mandate islands offered especially useful positions for airfields, coastal defenses, and logistics. Those fortified islands could function as fixed, unsinkable-carrier positions around the approaches to the Philippines. An American relief force might then have to conquer or neutralize each base before reopening the route. The counterfactual shows that treaty clauses governing infrastructure could shape a campaign as much as the headline limits on battleship tonnage.