That would indeed work. But the utility of Vandal is to not just support navigation but also to present an alterative vision for time-travel :D.
Not sure what permissions are needed to get the current url from the plugin though.
But if it's really more about a good way to browse the way back machine I think a web-service/site would make more sense. Installing a browser extension is quite a hurdle for something you don't need that often.
Too bad bookmarklets are not really a thing anymore, that would work well.