^^^^^^^^^ Agreed !
That cam chain is a multi-plate 'silent' design which is way overbuilt for the stress it sees driving those cam sprockets - in a clean, oily environment. Chains Do Not Stretch, their pins wear out due to lack of lubrication. I do not see that happening inside this engine. Since the shop did replace the cam chain, ask for it back. Measure 25 pins worth of stretched length. Take this measurement on any length of this chain at random. I doubt there will be any measurable variation outside of the accuracy and repeatability of your method. Have a look at the teeth on the cam sprockets, on the crank shaft sprocket, you will not find much wear after the initial break in marking. Look at the underside of the chain 'teeth' where it rides on the sprockets.
Reading the original post, I would be more inclined to look at the cam chain guides. If they are worn beyond a certain point the tensioner may not have enough stroke to properly take up the slack. What does the oil look like, was the oil filter opened up to have a look at what it strained out? The offending noise was reported coming from both sides of the engine, the cam chain is on the far right side. Did a mechanic use a sounding stick to try to pinpoint where this noise was coming from? Is the bike back together? Is the noise gone now?
I'm with Scooter on this one, the BS banner is flying high with me too! Me thinks this shop is making work for themselves. - BUT, that's just my HUMBLE opinion.
I'm the one who contacted American Performance Engineering way back in '07 to have them look into our issue. After supplying them with the necessary information they sent me a prototype to try on my '06 AE. I cut off the welded double nuts, hack sawed a screw driver slot, installed and ran it for several years. They also gave me one of the first production parts. It works as advertised, however, you have to make periodic adjustments, which most people have no clue how to do. It is very possible to do damage by running a manual cam tensioner too tight! About 7 years ago I had enough and put in the redesigned blue dot OEM unit. My '08 is running the current green dot OEM unit. It works well, and is out of sight - out of mind. So far, at 90K miles on the odometer, there is no loose cam chain noise at all.
Of course, Your Mileage May Vary.
Brodie