The CCTs don't fail because they can not extend far enough, that would be the chain failing: they fail as they are poorly designed - There is some debate as to what actually goes wrong with them though.
The chain "SHOULD" be fine after 37k - however as with anything you cannot be 100%
Did you ask how he adjusted the stock CCT? - they are autoadjusting: When my bros ZX-6R CCT went rattly i just popped it out and cleaned it (maybe that is his "adjustment").
I did mine a month ago if you need a talk through what you need to do - it is within the limits of someone non mechanically minded and it will save you a lot of cash. The worst then is that you change the tensioner, it doesnt sort it so you then have the chain done anyway.
CCT costs about £55 (UK) from davidsilverspares.com
Allow 3 hours for the repair (thats taking it very slow) - a mate to help with lifting/draining the tank will be worth his weight in beer too