I knew you were going to say this :)
This can indeed be solved with Change events and caching client side,
which is how I normally do it.
The reason why I proposed it is that I keep using that pattern over and over
and it would seem useful to have it "out of the box" instead of
the editor is often used for simple text input where strings are small but
may be constantly checked for (basically in forms).
For instance, I have an instance of a file selection widget where I let the
end users provide search patterns. I would like to just do an Editor.String
to retrieve the pattern and use that instead of doing the "check Change event"
dance for every input.