Hello!
Sorry for the long delay... I've been way busier than I would like, so I've been unable to keep up with the comments over here.
There is a parameter to tell the plugin categories should be opened or closedma whenever the menu is opened. You can find it inside the "Menu List Window Config" parameters:
If set to true, categories are loaded closed by default. If false, they load opened.
There is no function to change this setting dynamically. It should be on or off for the entire game.
Hope this helps you!