The check-brackets icon and the Ctrl-H hotkey do cause your code changes to be executed as if you had saved them to disk, and it clears your Ctrl+Z undo-history, but it doesn't actually save them.
If you cancel-out and click 'no' to saving changes, the changes since you opened the remotes editor or used Ctrl+S aren't saved to disk, and the script's timestamp doesn't change.
I think the placement of the check-brackets button is poor. It had taken a long time for me to even notice the button was there and that it was actually something to be used instead of being ornamental. I'd think that better placement would be down on the row near the OK and other buttons.
