I'll be nicer to have the dynamic notes in that preview window opening up on the click event of the icon rather than on hovering it. Then on another click it would close again. It's bit to much mouse moving at the moment cause one has always move to the red cross to close again.
I can say that once we're done working on Active Cases 3.0 I plan on putting in some time on new features for Active Compare. I'll take a look at doing this though and see about the possibility of having an option in the Control Panel for using the tool tip as a hover over or click event.