The minimum requirement for applying the Plans Theme in PRINCE2 is following the product-based planning approach. This approach involves creating a product breakdown structure, writing product descriptions, and defining product dependencies before developing the schedule and resource plans. It ensures that plans are focused on the project's deliverables and their quality requirements. References:
PRINCE2 7 Foundation Handbook and official training materials.

In PRINCE2, the project baseline should be updated when a change has been formally approved by the change authority. This is because the baseline represents the agreed standards and plan against which the project's performance is measured. Updating the baseline after the approval of changes ensures that the project documentation accurately reflects the current scope, timescales, and resource allocations, which are essential for tracking progress and managing by exception effectively.
(PRINCE2 7 Foundation Handbook, AXELOS)

Explanation/Reference:
Reference http://prince2.wiki/Manage_by_stages

In PRINCE2 quality review meetings, the recommended roles include a Chair, Presenter, Reviewer, and an Administrator. The Administrator is crucial as they organize the logistics of the review meeting, ensure that the necessary materials are provided to the participants in advance, and take on the responsibility of recording results and follow-up actions. Project Manager, Assurance, and Project Support do not specifically align with the roles within a quality review team.
PRINCE2 7 Foundation resources and study materials.