What of people who do not have a reasonable option to leave? Can the law not be applied to them?

And more importantly, what of people who decide to stay but explicitly confirm that they do not want to be a part of the social contract, benefits or otherwise? The option to leave is important because people staying when they could leave is an indication that they accept the town rules, and that indication could be overruled by an even stronger indication (explicit statement) to the contrary.

If you argue that people should be forced between leaving the state or accepting its laws regardless of their personal consent, then you need a moral justification for that, and we run into the same problem from before.