In case someone is interested in a work-around so as to be able to trigger an event when a container changes visibility:
We can put an empty block inside of the container, this “dummy block” can have 0 margin, 0 padding, no min width or height… so it’s basically invisible. The block is mounted/unmounted when the container visibility goes to True or False (see here). This means we can create our logic in the “on mounted” and “before unmount” logic areas of the dummy block.