I suppose to block light to any weeds that do make it through the cardboard and compost mulch.
Just identified dock weed on the site too.
There’s nothing to prevent a second layer of cardboard &compost to re-treat any emerging weeds, eventually you will win.This will enable you to plant out transplants the same day.
Docks can be dug out or tied to a lever and lifted when soil is moist. Just make sure they dont seed!Good Luck.
Cleansweep