Empower project staff to make decisions about methodology application and trade-offs between scope, schedule, and budget when necessary.
Rather than ‘empower’ staff, a decision-making process needs to be created and everyone told how to use it. Staff decision making has to be circumscribed by the staff member’s circle of responsibility, down with in project constraints and objectives and communicated to the relevant part of the project structure. Where business value or performance is affected, the project manager must know and a proper change process used.
If ‘project staff’ in general were to make the project-critical decisions that the Executive Board’s advice suggests, you cease to have project management and have project mayhem instead.