Nope. You cannot expand all parameters easily in the ECW. The windows should however retain all states once untwirled. They will only snap back to the top of the ECW if the panel is too small toaccomodate all of them and the you have to use the scroll bar to bring them back into view. If you need a specific parameter to be visible all the time, I recommend you add an "empty" expression (Alt+click) that only use the default values and then reveal all parameters using the U shortcut.