For an overall system, I'd erase the fairness, potential, and competitive aspects of testing and aim only at what tools get a kid to stay in their zone of optimal learning. And I would look to have services that meet their needs across their spectrum of abilities.

Given that that zone includes content as well as rate and other presentation factors.

As long as there are resource constraints, limited seating, norm-based testing, poor professional development, and "Jones" concerns, it's wishful thinking on my part.