We have some items that we ship out via Amazon MCF, we have shipping rules set up to automatically do this which is nice.
The issue is that the only option for sending our inventory levels to our stores are either 'FBA + our stock' or only 'our stock'. So for these items that we ship out via MCF, sometimes we have run out of stock in Amazon FBA and need to ship it out via our warehouse. For these instances we want our shipping rule to be able to tell when the Amazon FBA inventory is gone (or preferably when it reaches some threshold before actually running out that we can set, similar to the low stock threshold), so that if it is impossible for Amazon to fulfill our order, that the shipping rule doesn't try to send the order automatically to Amazon where it will fail and eventually return to our orders page.
We really need our rule to be able to know this and not send the order off to Amazon. That way we can see right away that we need to fulfill the order ourselves.
I realize that the best option is simply to not run out of stock in Amazon, but sometimes this is not possible due to choosing to not restock those items in Amazon or other reasons. So we still need the functionality in ShippingEasy to have the rule first look at the Amazon FBA stock and base the rule only on that stock.