/etc is writable, so no reboots are required. That said, /etc is treated in a special way and each deployment will have its own /etc, based on the previous one.
So if you make changes to /etc then revert to a previous deployment, your changes will be reverted as well. But if you make changes and upgrade (or do whatever to create a new deployment), your changes will bu preserved.
Is etc the mutable part? Would you have to do this again to add more users after a reboot?
/etc is writable, so no reboots are required. That said, /etc is treated in a special way and each deployment will have its own /etc, based on the previous one.
So if you make changes to /etc then revert to a previous deployment, your changes will be reverted as well. But if you make changes and upgrade (or do whatever to create a new deployment), your changes will bu preserved.