Maybe I didn't explain this well in the help file, so I'll explain it here.
The autosize engine sends an event to the form which is:
This event is sent when the form is resized, indicating the autosize engine has a resize table.By default the engine does not resize the controls!
You need to process this event like this:
This will cancel the event and the engine will then auto resize the controls.
By processing this event you explicitly tell the form, to let autosizing occur.
By using an event to in essence allow you to turn autosizing on and off, it allows you to override the autosize engine.