The useMemo hook is being used to memoize a constant array PROMOS, but since PROMOS is already defined as a constant outside the component, using useMemo here is unnecessary and adds overhead. You can directly use PROMOS in the component or simply assign it with const promos = PROMOS.

The screen reader fallback text only displays content when active.label is a string, but in this implementation, both promos use ReactNode (JSX elements) for labels. This means screen readers will never receive alternative text for the rotating banners. Consider extracting plain text versions of the labels or implementing a function to convert the ReactNode content to text for screen readers.

The automatically rotating banner doesn't provide users with controls to pause, stop, or manually navigate the rotation. According to WCAG 2.1 Success Criterion 2.2.2 (Pause, Stop, Hide), content that auto-updates or rotates for more than 5 seconds should provide a mechanism for users to pause, stop, or hide it. Consider adding pause/play controls or allowing users to navigate between banners manually.

The color #001a72 is hardcoded in multiple places (lines 33, 42) in the CSS. This dark blue color doesn't appear to use CSS variables and may not respect the theme's color mode (light/dark). Consider using CSS variables for colors to maintain consistency with the rest of the site and support dark mode properly.

The wrapper div uses inline styles for flexbox layout. While this works, it would be more maintainable to define these styles in a CSS module file (e.g., in the Navbar's styles.module.css or a separate file) to keep styling concerns separated from the component logic and make it easier to adjust if needed.

Users with reduced motion preferences will still experience the automatic sliding animation. Consider respecting the prefers-reduced-motion media query to disable or reduce animations for users who have indicated they prefer less motion, which is important for accessibility and can help prevent motion sickness.

The sr-only class is used but doesn't appear to be defined in the codebase's CSS files. This class is critical for screen reader accessibility. Either this class needs to be defined in a global stylesheet, or you should use a CSS module class from styles.module.css. Without a proper definition, screen reader users won't have access to the alternative text for the rotating banners.

Direct usage of window.setInterval and window.clearInterval could cause issues during server-side rendering (SSR) in Docusaurus. Other components in the codebase (like RadonBanner, Wave, FooterBackground) wrap browser-specific code with BrowserOnly or check ExecutionEnvironment.canUseViewport. Consider wrapping this component or its interval logic to prevent SSR errors.

The rotating banner doesn't announce changes to screen readers when the content rotates. Consider adding an ARIA live region with appropriate politeness level (e.g., aria-live="polite") to the wrapper div so screen reader users are notified when the banner content changes.

The banner links don't have visible focus styles defined. Users navigating with keyboard will not see a clear indicator when the banner link is focused. Consider adding a :focus or :focus-visible style to provide clear visual feedback for keyboard navigation, which is important for accessibility.