From what I know, Omnis doesn’t really expose full programmatic control over IDE windows (Method Editor, Studio Browser, etc.) the same way it does for app windows. The notation and window commands are mostly limited to runtime/UI objects you create yourself.
The Classes command group is about as far as Omnis officially goes for IDE automation. Things like detecting which Method Editors are open, moving/resizing IDE panes, or changing focus aren’t supported via notation or commands, at least not in CE or Pro.
Hope that helps a bit.