"No dig" in Pots

I've often wondered about Charles Dowding methods ongoing? If I cover with cardboard and then compost and plant through it what am I supposed to do when the crop is harvested and I am redy to plant the next crop in the same area? Do I cover with cardboard again and add compost or do I just add compost? Because I have a never ending supply of cardboard and to save on the cost of compost, is it not feasible to strip off a couple of inches of soil and add to wheelbarrow, after which it will be returned on top of the cardboard?

To hypothesise on your query Veggie I would say that in open soil worms would be an integral part of combining the layers of soil and stopping compaction. In a pot, you probably wouldn't have the worm population or any invertebrates to break down and mix the layers?