> For those who don't know, laws are different, sometimes in major ways, when you cross a state line

That seems like a recipe for a huge disaster that we should rectify.

It's incredibly easy to cross state lines without purposely intending to, especially in the northeast (e.g. you can easily be ushered into NJ trying to get to upstate NY through NYC). It's exactly why 'safe passage' laws exist, even if it doesn't apply in these two scenarios.

It's not as though there's a customs check point at interstate boundaries where you are urged to dispose of materials that might cause you to be in violation of another state's laws.