Just thinking, I saw a patent application from the 60s that would seem to prevent every 3D eye we put on a hard bait. But, seems we don't have an issue so far.
I have been doing that style of weed guard for 45 years on my bass flies, just tied the monofilament instead of using a slip piece of rubber.
Patents applied for don't seem to protect, as indicated by CNC, and enforcing patents seems pretty hard as well.
I am glad that for the most part I am a hobbyist. I suspect that there is a patent for how I breath air, and a lawyer willing to sue me over it. I know that someone has a patent application for just about everything else, including time travel (search it out). ROFLOL