Team members (@bananajoe.games) already have full access to everything and are not listed here. Use this to give an outside email (a freelancer, an ads manager, an artist) access to just the games you choose. Viewer can look but not change; Editor can also edit. Changes save on their own.
Heads up: this page records the permissions. The enforcement (the actual lock on the Planner and the Hub) is being wired up next — until then, treat this as the setup step.