I guess we all have had in our bags 2 identical stackable items that won’t agree to stack. This is an idea to address this issue 
Kind like the container fixing machine (could perhaps be done in the same machines?!), a place where we can put an item (like an ingot for example) that doesn’t stack with same item despite its stackable nature (probably reason of old/new item id or something like that), but the machine would transform the item into a stackable one ( the new id)
I thought of that while crafting … I mean, that’s usually how I fix the “2 ingots that don’t stack” issue … By crafting something out of them. The crafting system recognizes both ingots for what they are, and is ok to use them both to craft. It’s also basically what our beloved containers do … When fed with un-stackable items, they give us back stacks. But as there won’t be ingot container for example (or grenades), the machine seems like the solution …
So, basically, we’d put an [old id] item (or stack, as they do stack together) in the machine and would get a [new id] item (or stack) in exchange.
Would be a blast … Thanks for considering! 