We have a two story Nuc with a total of 8 deep frames that is doing well.
The bees are still drawing out some comb though.
It's getting filled with nectar, pollen and sugar syrup as they go.
Do I need to be concerned about them becoming over-crowded or swarming?

With what I'm seeing I would normally put on another super with four more frames but it is late in the season.
I may be able to take some unused drawn comb from the other hives if that is an option.