All of that said (and believe me, I sympathize with your predicament) we still have to reiterate (what Adrian said) that THE No. 1 Big Important Thing with an AVL is to have the most top-notch battery possible all the time.
If the battery is not up to snuff, it cannot crank the starter powerfully enough to get the piston over that magic TDC point, the piston WILL be driven back down Backwards and that is what the Big Bad Horrible Noise is.
I do not doubt for an instant that there are AVLs sitting in back rooms or garages out there whose owners have destroyed the sprag by continuing to crank when the battery is just barely able to gasp out one more little nudge and Klank! and continuing to do it again. And again. And again. And then they blame anything other than their dumb selves and badmouth the bike.
I don't think there are many of us left out there anyway so so what? Mine still works fine when I use it, but I must say I have a very low mileage bike and have been a kickstarter my whole life. The Enfield is the first E/S I've ever owned and we knew already that the Sprag was the weak point to be babied (and never used if possible).
I've often said the AVL has one of the handsomest engines there is, but of course mine's a humble Iron Barrel. Your point's well taken though about the importance of tip-top battery state for the starter, regardless of model, but again, my batt's fine. Coming from the Sailing thing, where obsessive care for one's house batteries is a common characteristic, I probably measure the state of mine far more than most. In fact, I had taken the multi-meter to it that very day before even firing it up. Besides which, I didn't use the starter at all that day...hadn't used it in more than a month, and then only as a test after a good long run, as I'll do from time to time with clutch engaged just to keep it limber, but really that time just to show a fellow who was interested in the bike. No problem.
That starter decided to start acting up and getting all "grabby" all on its own. I cannot speak for its treatment during its first 4,200 miles or so by its previous owner(s?). I'm fairly certain the fellow I bought it from rarely ever or perhaps never kickstarted the thing, as I do. At least, when he showed it to me he only used the electric leg. But on my watch the thing's been pampered and very seldom used. The fact that it then shat the bed all the same without even being used that day gives me, I believe, every right to complain, and yes, "blame" that starter and its cockeyed design. Indeed! Once I've extracted its offending sprag lumpage, I shall summon up and visit upon it all the Demons of Heck, seal it in a sarcophagus with pharonic invective inscriptions, and cast it into yon furthest dankest corner of my garage along with those clogged steamship parts and radio tubes (Why the heck can't I ever just throw shit out?)...
How the Bilgemaster might appear
in full Springtime ceremonial regalia
exorcising the demons from his 2005 Bullet 500ES
Henceforth to be known as a "500ES"