The delivery process I ran for an enterprise telecom account and that leadership extended company-wide. Nothing enters a stage until client and team have both signed off on the one before it; a missing signature returns the work to the previous stage.
Scope changed mid-sprint and every slip became a dispute. A documented, dual-signed decision at each stage replaced memory with evidence.
The client learned to prioritise because the system required it; engineers got protected sprints because nothing reached them half-defined.
Work reaching development was ready to build and deploy, never reworked mid-sprint because the requirements were wrong. The standing QA backlog cleared.