And why not just have Freeport administrators who have a POB with weapons platforms who can put NFZ violators on the POB's hostile list?
Also, Zoners are a diverse group of people who wanted to leave house space.
That's it.
They're not all pacifists by vanilla lore.
They're not all people who shoot only in self defense by vanilla lore.
Those two things are just what early discovery Zoners try to make Zoners so they can go everywhere without getting shot.
But it's not logical, and it's not a necessity.
If it were logical, Zoners wouldnt all share the same diplomacy on every Freeport and wouldnt be neutral to all of Sirius, but would have different diplomacy on every Freeport. Just like Freelancers dont all have the same diplomacy.