Not in my experience, previously ran it setup externally with a shared library for at least a year or longer, https://support.apple.com/en-ca/108345. Typically I backup to external drive 2 ways, copy of library itself and unmodified export, only had to go through above after I needed to rebuild the laptop. OP app and or https://photosbackup.app/ , seems like they might enhance my setup, will have to take a closer look.