Question: How can I create my own instance of an existing struct?

[matl4c]

I understand how to create an instance of an existing class...

const AssemblyCSharp = Il2Cpp.Domain.assembly("Assembly-CSharp").image;
const interestingClass = Il2Cpp.Domain.class("Some.Namespace.interestingClass");

let myInstanceOfInterestingClass = interestingClass.alloc();
...

If the namespace Some.Namespace has a struct of interestingStruct, how would I reference and create my own instance of that?

[vfsfitvnm]

Create the object, then call Il2Cpp.Object::unbox to get a Il2Cpp::ValueType (a struct).
PS: Il2Cpp.Class::alloc only allocates the instance: its constructor will not be invoked - you need to call it aftwerwards like any other method:

const myInstanceOfInterestingClass = interestingClass.alloc();
myInstanceOfInterestingClass.method(".ctor").invoke(...);

// shorthand to alloc + ctor (but without arguments)
const myInstanceOfInterestingClass = interestingClass.new();