On Saturday, May 2, 2020 at 8:46:39 AM UTC-4, wrote:

How would a CFI, observing from the ground, evaluate such elements as proper use of controls, scanning, discussion of safety options, slow flight, stalls, stalls departing toward a spin, and any number of other important items?

A Flight Review is not a Checkride. What is actually required? A couple of GoPros in the cockpit could answer a lot of your points.

I'm proposing a stopgap measure that would be a lot better than people flying with expired flight reviews (which I expect will happen), or flying dual with a CFI that has underlying medical conditions.

My flight review is valid until July 31 2021.