I can’t seem to find solution on this after i successfully added a custom column under cataloginventory_stock_item table and added field in inventory.phtml. It does save the value when editing the product but the problem is when i try to add cart the product which was set as backorder/preorder enabled and then is in stock it says “The requested quantity for “Floral Strapless Maxi Dress – Cream” is not available.”. So it won’t let you add the backorder/preorder item to cart.

I found one post saying about if something is modified in inventory stock it will have a problem as stated here: "The requested quantity is not available" Back Order Products

But on that post the only solution it suggest is remove the code, I want to make it work is there any solution or alternative way to have custom added field for inventory stock item table?