I've updated this to 1.1.
The update adds support for doubling the end token from just }: to }:}:. Doing this causes a collapsible block to not save its state in the editor when it gets opened or closed in the webview - so you can have it be always opened or always closed when a note is initially loaded. There was already an option to do this globally in settings - now this option allows it on a block-by-block basis.
So a block like :{:{this}:}: will always be initially opened when a note is loaded, while a block like :{this}:}: will always be initially closed when a note is loaded. You can still open and close them in the webview, they just won't remember that state when the note is reloaded.