Thanks for reaching out.
With ATUM Multi-Inventory add-on you can create as many inventory records per product as you need. You can allow your customers to select from which inventory they would like to make an order.
Although, Multi-Inventory doesn’t have the option that specifies “future stock”.
However, what you can do is create an inventory that allows backorders, so the customer can order the product from this inventory.
The backorders indicator will display the number of items required by customers in your Stock Central.
Please, note that the backorders will be shown in the Stock Negatives in your Stock Central, and you can easily view the products that are with this status.
So, the customer can make an order from the inventory that IS in stock, and from the one that allows the backorder (with zero stock).
I’ll leave you here the documentation about how Multi-Inventory works.
Also, here you can try a demo version of Multi-Inventory to try it and see if it suits your business.