I do blanche peas, but they are sugar snaps. Just half a minute. Same with broad beans.
For freezing, I put them into large zip-lock bags layed flat on trays, then once they are frozen I shoogle the bag until they are all separate, make sure all the air is excluded, then extract portions as I need them. I find this takes up less space than freezing in boxes, and the air can be kept out even when there are not many left in the bag.