If the devs are reading this, I found a bug: if you use the wikipedia bang and search, say: "!w knot theory" the actual search page it brings up is for "knottheory" without the space.
Also if you search for just "!w", you don't arrive at the English Wikipedia front page, which is the behaviour I'm used to from DuckDuckGo. "!bbc" should also lead to the BBC front page, etc.