I think the strength argument doesn't really have legs. SRF engines are fundamentally similar to the Fit (i.e., a bog-stock production motor with output roughly that of the street application) and those engines DO last significantly longer than the FF numbers I've heard.
So it's possible the Fit engine has some flaw,that Honda isn't aware of. It's also possible that an asteroid will slam into the Earth tomorrow morning and make this entire thread a moot issue
Steve