Your comments

Control-0 to focus and up/down/left/right/enter work great but it doesn't support typeahead.  If I hit 't', I would be expected to be taken to files beginning with 't'.  Instead, alphanum keys just seem to be ignored.

I'm not sure this item is actually complete yet.

Yes "Show Results in Buffer" is key.  I didn't understand this button either.

Also, is it possible to make Super+Alt+B toggle it?  Reaching for the mouse and hitting such a tiny button ain't a great use of time.  :)