Thank you for adding the new page banner module!
We have several use cases for this module; however, we have concerns regarding user experience. When a Forge app has a page banner in its manifest, it’s rendered on all pages. This means that the iframe with the app code must be loaded first before the app can determine whether the banner should be displayed or not.
While the app code is loading, Confluence shows a large loading spinner. This can cause a significant layout shift, especially if more than one Forge app with a page banner is installed:
Display conditions could partially solve the issue. However, in our case, we need to implement our own business logic to determine whether the banner should be displayed or not.
Since page banners are not primary UI elements, I think that no loading spinner should be shown at all. This would mean that the banner would only affect the UI when content is actually being rendered.