Accounts
Your keys, with a clear purchase source
Assignment decides where a key is used. Its original purchase source still controls billing and renewal.
Account & licences separates the pool from the keys assigned to this Controller. Moving a key is an assignment change; it does not turn an Apple subscription into a web subscription or create a second entitlement.
Review the source and validity shown on each key. Manage an Apple purchase through Apple, and a web subscription through the web account. Granted keys are identified separately and do not imply a recurring charge.
An offline reservation may still belong to its previous Controller. Follow the release flow and read the current state before assuming that capacity is available elsewhere.