Interesting. I insert the flyline into the core of the buried tag as described in step five and find that I get a good transition from the line through to the loop without a hinge at that location. I wonder what's different. In fat lines that won't go into the core I will strip the coating off the last inch of the fly line to expose the core, then insert the that piece of flyline core up into the buried tag. Generally I have only had to do this with floating lines 10 wt an up.