From my personal take on this and from fellow officers that I work with, you will get a different answer every time, but my answer is probably more informed since I am a knife enthusiast
Knife restriction laws are only really enforced if a crime has been committed and an "illegal" blade is found on the subject and is given that added charge. No one I know has ever charged anyone to date with a weapon charge for a knife - gun yes, but knife no. The knife is simply confiscated if it's illegal to own and the person sent on their merry way. I haven't confiscated anything yet because like the trooper example above, if they aren't a threat to me then they are OK in my book to carry whatever they want.
I did have to educate a lot of my fellow Deputies on the DIFFERENCE between spring assist and full automatic. One of the guys almost picked up a SOG Flash II black coated combo edge from a walking subject that was in a problem area in the middle of the night. The guy was just walking home late from a friends house and knew the address off hand and his ID showed his home was just around the corner. He was patted down prior to finding this out by another deputy and the knife was discovered. The other deputy flicked it open and of course the spring assist kicked in. He spewed out that it was an illegal knife and preached on his soapbox about how the guy could get in trouble for owning it. The subject readily offered to give up the knife and that he had no idea and did not want to get in trouble. I pulled my friend aside and explained to him briefly that it was a spring assist knife and not an automatic. I finished the contact with the subject, handed him his knife back and said "Nice Flash II." He looked confused and said, "Thank you, but it's a SOG not a Flash II, I picked it up at Lowes so I thought it was legal?" I told him the brand is SOG and the knife model is a Flash II. I also advised him that it was legal and that spring assist was a whole other thing from automatic. He walked home and I felt better for saving a fellow knife enthusiast from losing a $50 knife to my misunderstanding friend
If you stay under the radar you have nothing to worry about, J.