That checkbox is doing what it says: when you double-click it extracts (to a temp folder) the content of the archive so you can maniplate it.
It looks like you'd benefit from reading the manual a bit. You'll find there what are the commands behind buttons and misc. actions you can trigger, how all options/arguments to this command can make them suit your needs. It will help you understand the logic behind Opus and prevent from asking for features that already exists just at the reach of your hand or stating things are not working as they should, when in fact they're not working as you'd like.
As for the specific answer to your question: you can put it at the very same place I indicated in my previous post.