Please look at bringing stacks into preview mode. It is completely useless only being able to use it in design mode. Not having the ability to actually preview it means that I can't use it to build my components as I need to be sending everything off as previews for presentations. There's absolutely no value in ever building anything in a stack if the features don't carry over. This has led to countless hours of redesigning complex components due to a feature that was flaunted but has no actual purpose.