This may seem silly and very counter-intuitive to a collapse-o-matic plugin. Even so, i'll propose it. There are some instances in which i would like to easily display static content in the same style as that of my collapsible content. It would be great to have a shortcode attribute that locked content as expanded, no matter whether anyone clicked on the trigger or clicked on a trigger with a different rel attribute or a matching rel-highlander attribute.
P.S. With thanksgiving approaching here in the U.S., i want to say thank you. And with all my questions, i'll be sure to support your plugin development before the year's end. Thanks!