My statement regarding the length of the blade in the folder has nothing to do with the legality of the larger blade. IMHO blades that are over 3.75 have no practical use in a folder while adding unnecessary length, weight, and bulk. ie 3.75" blade in a folder can handle 100% of the tasks of 4" blade. If I need a larger knife I will grab a fixed blade. But YMMV if you want to schlep around a large folder go right ahead (I never said you cannot do it).
PS: if you must know, despite me being from NYC, I am pro-gun since it is not the business of the government to tell a grown ass man what he can or cannot do.