I saw hundreds of these butterflies yesterday in the Rob Roy foothills near Conder. The following reference says that the family Lycaenidae to which this species belongs has the habit of hilltopping: http://www.environment.nsw.gov.au/determinations/hilltoppingktplisting.htm Is that enough evidence to suggest this species does it too?
They're not really a hilltopper species like many other Lycaenids but they can be very widespread and abundant over all suitable open habitat, which includes open grassy areas around hill summits. If you check the ACT field guide, for each species I've listed under the notes section whether or not they hilltop, and how strongly they hilltop. For example, the ant-blues (pages 154-159) are dedicated hilltoppers and are rarely to be found away from summits.