Job allocations in the hive and reentry delays

I know that nectar is passed on by the foraging field bees to in hive workers who chew it up and process in before storing it in the cells.

I also know that pollen is packed into cells by the in hive workers who also chew it and add honey and enzymes.
The question is does anybody know of a reference as to whether the pollen is actually passed to in hive workers or is packed into the cells by the foraging field bees themselves before being processed.

This all arises because I am wondering about the periodic build up of bees, in flight, outside hives usually late morning or mid afternoon. Is there a delay in reentry due to security (aka airport queues) or insufficient in hive workers taking the nectar and pollen?