As in fly a scanning pattern around the focus point and look for mirrors that blind the drone instead of frying the tower.

Should be crazy efficient compared to the terrible alternative which would require something like deliberately de-focusing all other mirrors only to be able to verify that the mirror under test actually does project the sun where expected.

Tempted to keep my initial upvote on the "investor hype" sibling, out of spite for all projects that do, but the ability to check arbitrary points in the nonilluminated volume for accidental illumination must really make do much of a difference I can't. Thanks for pointing me in the right direction!