Pollen patties in September — do they build better winter bees, or a waste when natural pollen is pouring in?

Question for the nutrition-minded people. Twelve hives in Quebec, goldenrod and aster pollen coming in by the basketful right now — the frames around the brood look like a paint chart. At the club meeting half the room said they put pollen patties on in September "for the winter bees" and the other half said that's marketing. My understanding is that winter bee fat bodies come from good protein nutrition during the weeks they're reared, mid-August to late September here. What I can't work out is whether a patty adds anything when the natural pollen is this good, or whether the bees just eat the natural stuff and let the patty go mouldy. Where I could see it mattering is a dry year, or a yard with poor fall forage. Has anyone actually compared? I'm not against spending the money, I'm against spending it for nothing. Beginner-level answers welcome, I'm asking on behalf of the room.