Given a cross-wiki notification bundle with enough notifications to make it taller than the current viewport, once it is expanded it pushed the panel footer out of the viewport:

The panel footer is expected to become sticky, which happens only once you start scrolling after expanding the bundle.

In addition, if you did some scrolling and collapse the bundle again, the panel won't readjust its size, keeping some gap between the notifications and the footer:

These are some edge cases which probably require very specific number of notifications, so may not be the most urgent thing, but since I encountered them I wanted to capture those.