Without looking at Ferrari Chat I’ll wager that unchecked exhaust leaks lead to burnt exhaust valves, damaged valve seats, and homelessness.

What, the rebuild or driving around? I’ll presume you mean the rebuild. My guess is that it causes problems with the exhaust valves getting the scent of open air and freedom, thus deciding they no longer want to be exhaust valves. Instead, they become tiny bits of molten metal which end up all over everything, thus…