It's not a matter of any kind of compensaation. there is NO flare at all in the aluminum section
I have lost all faith in my dealer. He can't even charge a credit card correctly, much less cut a shroud the correct length. A less obvious problem such as this would be completely beyond him, and I would have to bring him the boat and leave it for a couple of weeks. Plus four hours of driving and I would probably be charge a diagnostic fee for him to not fix it. Forget it.
I actually have done as you have suggested and dinged my new mast sections up with pliers and put a flair in the end of the aluminum sections. So far so good on the lower aluminum section, but the bolt rope still pops out of the upper one. By the way I even replaced the halyard with ultra low stretch. One of the first things I did, since the factory halyard elongated much too much and allowed the headboard to creep down the mast below the top aluminum section with the inevitable result. The new halyard has helped that issue but now this problem of the bolt rope exiting during the hoist.
I mentioned the slug idea. You mentioned that there are other problems that come up. I would be curious to know what they are. Double slugs fitted to the headboard seems like a promising solution from my vantage point.
Can you sell me a single continuous section of aluminum mast track? That would be ideal and would solve all these problems. Oh wait, that would be conductive and defeat the purpose of the comp tip. Oh, wait... the reason I had to replace the comp tip was that it exploded when hit by lightning because it wasn't conductive.