The new Fix had better be flawless 100% of the time, because Boeing is now helplessly wedded to this monster, and any further crash may well have dire consequences for a company whose reputation is teetering badly.
And I think you should have put ANY in capital before "further crash" , Because the next Max that goes down for ANY reason will cause a huge steer up and the Boeing situation will become unattainable, even if a year after an NTSB report establish that the cause had nothing to do with the aircraft itself. The period between the crash and the report will be too long for people to wait to regain confidence.. We unfortunately live today in instant news and requiring immediate answers.