@jaffathecake is there an article somewhere describing *why* select is hard to style? Structurally, not just due to current browser limitations, since this is a structural change?
I can definitely see why you don't like the copy approach, but… either I'm missing something or this seems like it would be rather easily handled by toggling an "is expanded" attribute on <select> and hiding non-selected things. I'm not seeing how the button and nesting solves problems proportional to what it causes.