highly recommends the users to login as the root user and not the guest, equally. This gives more freedom to the users over their system. The Guest account lacks many privileges and features that are present in the root account.
Also, to install Granular, you need to be logged in as the root user.
The only thing for which you need to careful about is that don't mess up with any files that may affect system's stability while logged in as root.
You'll enjoy the Granular experience more through the
root guest/standard user account.
P.S.: We are assuming that you are using Granular either for your personal use or for your home computer(s) and not in a business environment.