We allow "Continue selling when out of stock". This is something that is common in our business as many items are ordered by us from suppliers only when a customer orders them from us (they can be quite large or expensive or out of stock with suppliers or all of the above). BUT where it really hurts us is when reviewing orders, new and old, the only way to verify that we have stock and that the order is ready to ship is to open each product from an order in a new tab, one at a time.
This gets old mighty fast!
Just showing the number of in stock items beside the order line items or a coloured dot (red/yellow/green?) for stock levels would save us immense amounts of time and gray hair and give confidence that we're doing the right thing. It would also give us a nudge where we need to order more of an item if we see it's running low.
If you run into this too, please put in a feature request to up-vote a solution for it (It looks like the process for feature requests is to submit a technical support ticket through the Help).
Any suggestions on how to make this process easier are welcome (I suppose suggested inventory management apps as well, sigh...), but we would love to see it natively in Shopify as it seems like it's a quick win and an obvious improvement to remove a pain point for anyone allowing selling while out of stock, and it would help avoid accidently sending fulfillment notices when the products aren't actually available to ship, which happens from time to time and aren't great optics events with customers.