This writable enum sets which firmware copy, temporary or permanent, a blade will boot from after its next reboot, showing and refusing to accept a set on notApplicable blades; the recommendation is to stay on temporary unless it's proven unreliable, in which case switching to permanent is a fallback. It matters as the mechanism an admin uses to roll a blade back to a known-good firmware copy if a new (temporary) update turns out to be problematic. An admin who suspects a firmware update caused instability would set configurationBladePendingBootMode to permanent(2) and reboot to fall back to the older, presumably stable copy.