That makes sense. It's not something I'd considered. However, this is not exactly what I had in mind. My thought was that society should have, as you've put it

That makes sense. It's not something I'd considered. However, this is not exactly what I had in mind. My thought was that society should have, as you've put it, "reasonable limits on free speech" but these zones should be "free speech absolutist" places. So the scale is from absolutist in the zones to regular in normal society rather than normal in the zones and restricted in normal society. Whether the former will collapse into the latter and how to prevent that are serious problems though.