B2B Out Of Stock doesn't create a back order automatically when Multiple Deliveries selected

We have noticed that when we Allow Backorder and a customer selects Multiple Deliveries; ship all available items now, ship currently unavailable items we need to look at the notes to see they selected:

Single Delivery; delay whole order until all items are in stock

Multiple Deliveries; ship all available items now, ship currently unavailable items later

And if Multiple Deliveries are selected we need to create a backorder manually. 

However, when we create an order manually in DEAR and the product is out of stock DEAR creates a back order automatically. 

It would be great if backorder would be created automatically if customers select multiply Deliveries.