Regarding knife laws in different locations across the country, Knife Rights actively works to get legislation repealed or adopted in favor of knife owners.
They also have an app that helps to guide users through the laws in 50 states and 40 cities. The app can be found at:
https://kniferights.org/resources/legal-blade/ .
In general, it is best to carry a knife that is conservatively permitted under the law wherever you are in order to try and avoid adverse reactions from the public as well as perhaps zealous law enforcement officers. And if asked by an officer why you are carrying a knife, you should never reply "for self defense" since in many places this would then qualify the knife as a weapon--which is generally prohibited.
Sometimes, the display of a knife can be out of place. In a corporate setting, I was sitting in a meeting when an engineer pulled out a large pocket knife and proceeded to trim a fingernail. Even though I owned knives that would put his to shame, my reaction was one of surprise and thinking that this was not the place for such a knife to be flaunted.
If done in many situations, such a display can lead to complaints by members of the public who might feel "threatened." Consider New York City where the police arrest people carrying otherwise legal knives that expose a pocket clip--the law allows them to assert that it is a "display" of a threatening nature. Lots of people have paid fines for carrying such knives, and I suspect they then have a criminal record. Knife Rights has taken this on, but I am not sure they have won out yet.
Larry