Remember, Google? "Opt-in". Or in this case, at least "opt-out-able".
MS Office is a good example - the UI was customizable almost down to the pixel in Office 2003 and earlier. But in Office 2007, the redesigned UI - with the exception of a single small toolbar - is completely unconfigurable. An MS employee told me at the time that it was a deliberate decision to compromise customizability in order to simplify the interface for the plurality of users.
It's a shame to see Google making the same decisions. But least Chromium is open-source.
To use the url-mapping feature, you need to start your search with either a top-level domain name or a protocol specifier, or end it with a "/". If you just type a hostname on your LAN, it won't try to visit that location, because it's not a location bar. It'll search, and fail to trigger the Lucky feature because a single word isn't specific enough to be detected as a url.
Though, it seems if you put a "/" at the end, then next time you type the word, it matches against the history and gets it right.
Anyway, it's too smart for me. I have trouble figuring it out sometimes.