Is this still working in 4.24? I´m not able to reproduce those results. I have an editor widget, the Event Run and also turned on Auto run default action. I added the path to my widget in the DefaultEditorPerProjectUserSettings.ini but nothing happens on startup.
Update: I found the mistake. It seems like the subsystem is not loaded at the time it tries to get the reference in the run node. It is not able to validate itself.