>>moelf+(OP)
When installing graphene os I would consider very carefully if you want to relock the bootloader. In the past I have installed graphene os on my pixel 7a and a normal system update broke my system and made it unbootable. Because of the locked bootloader you can't reflash the os without wiping your data. It may be a very uncommon bug that may never happen to you, but honestly it shouldn't have happened to me either.