There's also #2620, but using this one as a task list for things that are remaining.

• Ensure the version in Capabilities is set correctly to a version that includes all the required flags
• Add support for multiple Flutter projects (currently we just pick the first one in the workspace) moved to Support multiple (unrelated) Flutter projects in the same workspace for Widget Preview #5671
• Pass DevTools and DTD server URIs so the preview doesn't start its own
• Add new icon for Sidebar version (this is in two places - container + view) moved to Update the icon for the Widget Preview when shown in sidebar #5672