Glad you had a good crop. Yes there is some soil mixing with compost although I find that most of the tubers pull out and I can find the rest by using a trowel to lever them out, after following their white stems from the main stem. Possibly you are being too vigorous as I would not call it digging. After harvest I walk on the bed to firm it all down again (except in last year’s rain).
Your Greenshaft peas sound a great success and show how peas like early summer warmth rather than midsummer heat, so it pays to start them early.