For example for Etherpad widgets, when in the sidebar, there is no way to popout the widget like before. Getting to the URL of the widget now requires clicking "Edit" and copypasting it from there.
Now when in sidebar, no popout action:

Before (and when pinned), popout action:

With the ongoing auth work it's not always possible to pop out widgets so I believe it simply will no longer be supported. Full screen interactions are planned however.
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With the ongoing auth work it's not always possible to pop out widgets so I believe it simply will no longer be supported. Full screen interactions are planned however.