Display back in stock notifier with custom stock status

Hi, is there an option to display the Email Subscription form each time that the stock status in not “in stock” ?
Because I have created a custom stock status called “pre-order” and I would like that client can enter their e-mail to be notified when the product is effectively “in stock”.
For the moment, the Email Subscription form only shows when stock status in “out of stock” or “on backorder”, but there is no other possibility in the settings of the plugin.
Thank you in advance, have a nice day !