I have EP for 3 kids and stopped around 2-3 months each time because it was a lot of work and I needed to travel/work/ etc. I was always able to freeze enough to make sure each baby had enough breast milk for 3-4 feedings a day for another 2-3 months. So basically while I only pumped for 2-3 months, my kids alll had bm for 5-6 months. I pumped a lot though and filled two freezers with each baby. I have no clue if there was any added benefit to be honest, but during my maternity leave I was able to do it so I did. I used a medela hospital grade pump (rented from the hospital) and pumped 5-6 times a day for 30-45 minutes each time... yes, it’s a lot but that made sure my breasts were completely empty and it increased my supply. I prefer that than pumping 20 minutes 8 times a day.