I've also noticed that it's not possible to edit Local Delivery orders. This is a bit frustrating as it's possible to edit other order types. I means creating new orders any time a customer wants to add (or remove) products.

I contacted support about this and they said that Local Delivery is only designed for products that are in stock:I looked into this for you and local delivery is only available for products that are in stock, so what you would like to do is not curre...

I would love to know how to do this too.