I'd agree that his experience would be useful to many orgs, but staying in his current career and earning to give would have more impact than job searching for year upon year, with lower likelihood of success as he ages - if his ultimate goal is impact.

Someone who is 57 years old with decades of specific industry knowledge seems like a perfect candidate for earning to give. Have you considered that route? You can still stay informed on EA and participate in events and groups, while working in your current career.