If this is indeed a common occurance, all because of banking hot coals in direct contact with the side of the bowl, then I would expect Weber to honour the warranty as this appears to be a glaring deficency. So far, Weber has replaced the bowl but I should think that at some point they may bawk and accuse some of wilfully damaging the bowl.
However, they say nothing about not banking coals against the side and as a matter of fact, say to do just that for indirect heating with the charcoal rails (that they sell). If they would want us to use the baskets, then said baskets should have been provided in the price of the kettle or a directive to not bank coals against the side.
No, I will continue to bank coals on the side of the kettle when I do a slow cook, and woe to Weber if and whenever the porcelain starts to crack. I will expect a FREE exchange or repair for the full 10 year warranty period. Of course what I expect and demand may be completely different to what I actually recieve.