Automation cloud obviously has both dictionaries and multidimensional collections - but collection operations don't by default support creating your own.
This limits what you can do with component workflows. For instance, I've created a component workflow that uses the graph api to read / write excel files.
Unfortunately, because the "add item to collection" action doesn't allow me to add a collection to a collection, I have to use a combination of building text string on the calling end to create text delimited data structures, then regex on the receiving end to split the delimited lines to collections.
That's tedious and cumbersome. I should be able to build a collection, then add it to a collection as an item within that collection. This would greatly improve the utility of component workflows.