I have been asked about where to see these parrots. This is not my area and I might only visit about once per week. There is plenty of info about almost daily obs in past reports on the chatline. However the following may be of some help.
From Duffy St at bottom of this map choose either the Foveaux (FO) or Fisher (FI) parking points. The Swifts might be in any part of the reserve shown on this map or in trees in gardens backing the reserve, They seem to be present throughout the day and are detected by their distinctive ink-ink calls (lighter and more rapid than the abundant miners) which will often draw attention to one or more small parrots in flight or moving in the tree tops. Most people have reported them in the trees enclosed by the red line. They also use the trees enclosed by the violet line, and that is where they were feeding on lerps today - intermittently over a period of 2 hours.