Pre-order for B2B when 'continue selling when OOS' is not enabled (based on customer tags)

For logged-in B2B customers (tagged “b2b”), I want them to see the Preorder button when a product is out of stock.

For regular B2C customers, I want them to see a “Notify me when available” (Back in Stock) option instead.

In other words, the preorder function should only be visible to customers with a specific tag, while others only get the back-in-stock notification.