I have replaced GoToolManager with my derived version supporting mouse and keyboard input. Everything works, but I have noticed that I must click the diagram in order to make my ZoomingToolManager working.
When I run my application neither rotating mouse wheel nor pressing keys doesn’t fire ZoomingToolManager’s event handlers. It doesn’t mean that the diagram is not receiving any input - mouse wheel scrolls the diagram up and down, so the default GoToolManager must be handling this event. After clicking anywhere inside the diagram, mouse wheel performs zooming - ZoomingToolManager is active.
I have version 126.96.36.199 for WinForms.