Enumeration is just a fancy coder word for "list of things". There are things called "enum" definitions in C#, and also an IEnumerator interface, but beyond also being "lists of things" there is not much connection. You get that kind of a drop down when you call RegisterStringChooser with a JSONStorableStringChooser from your MVRScript. Essentially its a List<string> simply containing the things you want in there. However, MacGruber_Utils.cs contains a SetupEnumChooser function that can create such a StringChooser from an C# enum type. Note that you can't create your own enum types in VaM plugins due to security imitations on using Reflection. However, you can use existing enums defined by VaM, Unity and C# itself.
Actually I'm not sure what they do myself, I never took the time to investigate. However, my assumption is that they can be used to manipulate presets via trigger. I think it can be used to store the settings into one of three slots and later restore these on another atom/reciever. Similar to how you can copy clothing materials from the UI. Note that this will very likely only function in context of the chosen "Receiver" and its corresponding JSONStorable, not the entire Atom. If you want the entire Atom, go to the designated "Preset" storables on that atom. (One of the examples shows this with a PosePreset)
