Sure. The easiest and most direct approach would be a questionnaire along the lines of "an FAA certification improves my confidence in the product (1: strongly disagree, 5: strongly agree)". Then just get every group you care about to regularly answer the survey.

You can also measure indirect effects, like how many agencies rubber stamp standards and certifications by the agency in question.

The interesting question isn't if it's measurable but if somebody measured it and is sharing the data