Organize boundaries
An agency can place each client in its own organization or use narrower code groups where the same legal and operational boundary permits it. Assign the team working on that client, and keep finance or owner accounts in smaller groups.
Handle staffing changes
Invite an existing Team2FA user to the relevant organization or group; outside users can create an account from their invitation. When a contractor finishes, suspend their membership and rotate shared seeds they might have copied.
Prepare for an incident
Identify two responsible people who can reach essential accounts. Store recovery mechanisms separately from shared TOTP and document which external service owner can reset access.