Thanks for the suggestion.
This is already done if the order is locked to a specific fulfillment site, either by locking the individual order or due to which sites the customer is allowed to have fulfillment from.
Often orders could use multiple sites, and if the site isn’t locked (especially if you let Breww automatically determine the best fulfillment site), then showing just the stock at the site which is currently expected to fulfil the order might be unhelpful.
I’m sure we can look at further improving this, but I wanted to highlight why this isn’t quite as simple as it looks on the surface. If anyone else would like to see this, please make sure you vote with the button in the top-left 