Hi Tom. The only reasons I understand why snakes shed are for growth, and also if the snake has external injuries such as burns, bites, cuts, abbrasions, etc.
By the way, very nice Grey-Band you have. Just curious, I know you said your alterna was small for his size and a problem feeder. How large is he? Other then his growth problem, he's an outstanding looking grey-band from the photo. I have an 03 alterna that's a freaken eating machine, at around 19 inchs. Wish I could give more advice on what's going on with your guy, but I don't have a clue as to why the frequent sheds with little or no growth. None of my Getula Kings have ever had a problem like you describe. Like one of the Vets told you, maybe it is weak genetics. That's a tough one to answer.
Steve