The extra usage billing display has been significantly enhanced with an overage credit grant system. Users may now see their available extra usage credit amount (e.g., "$5 in extra usage") along with the message "On us. Works on third-party apps · /extra-usage". The system fetches grant info from a new /overage_credit_grant API endpoint and caches it per-organization.
Evidence
Overage credit display (search for "On us. Works on third-party apps · /extra-usage") — LE6() at line ~424063
Strings lifted out of the shipped bundle, so the claim above can be checked against them.