Currently, when one of the pilots takes a break, they put a senior crew member on the flightdeck, so there are always 2 up front...
So it appears this is already happening...
Enthusiasts for fully automated flight might like to review the multiple Bulletins issued by Boeing over the last decade or so regarding flight path “anomalies” in both VNAV and LNAV in RNP approaches in FMC updates U11.0 / U12.0 / U13.0 etc.
Fixed now , but a reminder ; there is no such thing as fault free software.
Yes that was true, that is a problem with an technologically outdated FMS system running legacy software with 14 plus versions of software updates and patches.......