I've tweaked around with an adding empty stack replacement in a project of mine and ended up deciding it was out of scope and better handled by inventory tweaks. At first I tried making items in the hotbar represent all items of that type but it ended up being rather unintuitive because of the difference between what you see in the inventory vs the hotbar.

The latest iteration attempted to visualize that an item will be replaced when empty (you may notice the stack is doubled). It serves both as an indication that there is more in your inventory (useful when building), and also ensures you know in advance that the item will be replaced.

These features are scrapped on my part, and I figured it could perhaps be of use to you. I will be happy to share the implementation details if you need them.