I'd love to take this one.
There was a study funded in Manitoba in the nursing field. It's a terrible name, but it was called the Retention of Older Workers Project. The only group that objected to it was the nurses' union.
It was intended to capture people ready to leave the profession who went from being at the apex of their career to allow them to work a few days a week, or in a limited scope, to help train the next generation. There was funding for that program, so of course it's not sustainable.
The evaluations that came from both the student nurses and the facilities were very positive, because it alleviated the workload for the day-to-day nurses and there was someone who was at the height of their career to help with the knowledge transfer. It hit two different areas. It allowed someone who was a retiring worker to still stay connected to the profession they loved, possibly help pass on knowledge, and alleviate the burden in the workplace. But of course it came with some funding requirements.