I have been scammed repeatedly by Shopify on the charges on refund. In the last event, I got an order with high fraud alert, and ASSURED BY Shopify customer service that I WOULD NOT GET CHARGED ANY FEE FOR REFUNDING. Yet, when I checked the monthly bill, the charges still came in!!! I contacted CS and they admitted the transcript but still would not refund after multiple communications with them. Like you I am feared of customer who place large order and cancel afterwards. Unfortunately my bank acct is overseas and not the easiest to process cheques from the US. Any other platforms such as WIX / Square / Bigcommerce that does not charge for refund?