i usually try to avoid using save states but dealing with things required for 100% completion having extremely low chances of happening is one of the 2 things i'll make an exception for
(the other being as a safety precaution for crashes, which i've done a lot in this playthrough cos libretro's psp core does not take well to losing/regaining focus)
(i own the game on ds but since nintendo wifi is dead the onion knight sidequest can't be completed so. emulating the psp version, which doesnt have that problem)