When I retired, the thought of working a part time job crossed my mind. Then I realized that it would be about 20% of my working hourly rate. Then I realized, if I needed more money, I should have just worked longer. That was clearly the best option financially speaking. Since I don’t actually need more money, I found other/better things to do with my time.
If I was in the accumulation phase and felt I need to accumulate more money, I most likely would have just chosen to work a little longer. Maybe you should revisit your plan.