When I added this rule and clicked my grid's refresh button in the pager area, no progress indicator displayed but it should continue to display elsewhere.
It may also be possible to connect appropriate events, i.e. dataSource requestStart. I'm just not sure at what point in the chain the progress indicator is displayed.
Be aware that any grid refresh will cause the grid to redraw and if the user has a particular row or cell selected, etc, that state will be lost after the redraw. If you need to retain that state, then you will *have* tap into the various events to save the state before the refresh and then restore it after.