The global roles and rates are configured in the Admin area of the software. These roles and rates are globally used for new Accounts and Projects, but do not affect existing Accounts and Project rates.

What that means is that as the global roles and rates change over time, you will manually have to determine if they affect existing Accounts and then update the Account roles and rates individually so that new Projects can inherit these rates.

Making changes to the global roles and rates, and even to the accounts roles and rates, do not make any automatic changes to existing projects.