Tasks should stay assigned to one person (usually a designer or developer) for the lifecycle of the task instead of moving from person to person. The one person is principally accountable for Cantilever getting the work done. They are responsible for requesting required Strategic, Peer Review, and QA approvals.
For newer people it is hard to take overall accountability for a task in the Cantilever style/workflow. They don’t have the right context and ability to operate that veteran team members do. For newer folks, it can be more productive for a senior person to take assignment of a task instead, and then delegate a specific portion of the work to a newer person via a sub-task.
As a part of task clarification, PMs should add sub-tasks for any approvals they believe are required to consider the task complete. However, the assignee is also free to add additional approvals that would make them feel certain that the work is in good shape.