Feature Request: expose tabs.duplicate and tabs.goBack

[visua0]

I'm trying to migrate from Foxy Gestures to Gesturefy because I encountered a page where Gesturefy works better, but I can't replicate one script I was using. In Foxy Gestures we have full access to browser through executeInBackground(). Of course I'm not asking for all that, I just require tabs.duplicate and tabs.goBack for a niche script I made to essentially open the previous page in a new tab.

The resulting script would look something like this:

API.tabs.query({active: true, currentWindow: true}).then(tabs => {
    API.tabs.duplicate(tabs[0].id).then(dupe => {
        API.tabs.goBack(dupe.id);
    });
});