Another feature suggestion for the sidebar would be a new addition to the Appearance view:
Full Object
This would show the full content of that object in the sidebar, not just the links. It would include every blok, headers, images, callouts, links, files, bookmarks, etc.
This means you can create a completely custom sidebar if you wanted and would also mean that not everything would work well for the sidebar. For example tables, table of contents and inline sets would be to big or not work in the sidebar.
But it might be alright that not every block type can work in a small sidebar but that is up to the user to create their own object that works nice as a sidebar.
Also, if blocks are placed next to eachother they would be placed below eachother in the sidebar. Same as it appears on mobile.
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