This is such a clever hack of text expanders. I use one for Mac called aText, but it doesn't have the ability to listen for keys, only text replacement. I've been thinking of switching to a different program for awhile, and this may be the motivation I need to make the jump.
It's pretty annoying having to do a search in the universal search box, then click on a note, than do cmd-F, then cycle through each occurrence in the note. Seems like the most natural thing you'd want to do after doing a global search is see all the specific places it appears.