And, another reason not to extract a couple frames at a time, is because you have to clean the decapping tank, tools, extractor, buckets etc.. every time. Which is why most folks wait and do it all at once.
Putting another super on will give you MORE drawn comb.. it is worth 3 times its weight in gold. It will also allow the bees to protect those capped frames until YOU are ready to harvest them... But as already said, yes, you can. Pull a frame, decap it, spin the honey out and drop it back into the hive. The bees will clean it up and start refilling it again.