Your reasoning is exactly mine when i did the original SpaceCowboy......
Here are some build pics....yes I wanted the lighter cone... 1/2 the weight! Back then I used the molded version, only choice I had.
You can clearly see all the cut marks etc. When done , the joints were all as perfect as one could get. You could close your eyes and not find the new joint on NC. Harness choice should be fine. I did put a very thin slice of cardboard airframe tube 1/4in over the harness, so I could fillet it.....just to be sure. That's where my tracker was. placed in-between the loop, then both sides of loop taped to tracker box and antenna went up into cone. Tracker basically upside down...LOl
I polished the airframe by wet sanding with 400 and left it as seen. Good luck with your project and have fun!
Edit: almost forgot.... when sanding the filler on joint from NC to band, either protect the rear edge or put it in payload the keep from losing that sharp clean break-joint connection. I put the NC into payload ...so when sanding the filler, I was killing 2 birds with one stone.