Instead of a simple single town waygate, Damian installed access to all three. Edgeheaven was a small city, and Damian didn't mind having an extra market. Before his trade towns, Edgeheaven was providing the same middle ground that was accessible to all.
By just using unique Sanctum IDs for people of Edgeheaven, Damian could stop others from trying to access this exclusive benefit of being an Edgeheaven native. If people use the locals to do their business, like most trade town merchants do for the Sanctuary, he could add a restriction on travelling. Like one ID could only visit one trade town in a day.
After discussing how to operate and control the waygates, along with the registration process for the island locals, Damian and Lucian returned to Sanctuary. The Highsword members, willing to join the research or the academy, could come to Sanctum anytime they wanted to, with the waygates installed.