Yes, it should be $buttons in the third piece of code. For the rest, yes. The first part of the code is a modification of your function for loading choices. The second two need to go into your template where you’ll be using the buttons. Sorry if any of this is confusing, I was just trying to come up with a way that would avoid completely rebuilding something.
Although this is going to change the operation of that field anyway and will still require a manual update of all the posts that use the field. But as long as you don’t change the “label” value in your options it will avoid needing to do similar manual updates if you change the values again at some point.
