This approach was a total failure

Loop through the minimap. Find all elements which don't have children,
but do have a `.text()` value (this should be the lowest level nodes in
text content). Replace every character with its HTML equivalent.

I had hoped this would hide the text from window.find search, but it
didn't. Ctrl-F still picks it up the same whether you use HTML codes,
Unicode points, or regular text. Ah well.