Update: sadly this is not resolved. I think I do need a catcher hut that prevents the tosses from getting to the catcher villager. I gave my catchers 8 stacks of seeds until they wouldn't pick up anything else. The farm shot up in production for a while. But shortly there after, it has stopped output.
Does anyone know about villager behavior when it comes to food sharing and full inventories? Is it possible for the villager to drop seeds they are carrying in favor of food they are being tossed? Is it possible that a farmer could see a villager with seeds and decide they are not hungry? That sounds impossible otherwise the villagers would not have tossed food to my villager even when they'd just entered the hut.