I'm not sure why you believe this. Every discussion of PR's tax scheme, the issue of 183 days comes up. Even people with a passing interest are aware of this

I'm not sure why you believe this. Every discussion of PR's tax scheme, the issue of 183 days comes up. Even people with a passing interest are aware of this requirement. Sure, you can lie about it and hope you're not audited, but knowingly lying on your taxes is already broadly known to be a dangerous game.