Citrus indora has been used as a rootstock in the Wet Tropics areas of Nth Qld, because it is locally well suited.
I think virgata ( finger lime X round lime ) was discussed by W. Swingle as a potential rootstock in The Citrus Industry.
I have never heard of C. australis being used as a rootstock. It does get to be a reasonably large tree in the wild.
There are many other rootstock choices in Australia, probably better suited to high input horticulture, than a wild plant.
C. australis seems to be compatible with Citrus rootstocks, although mine seem to have overgrown the stocks, in some cases.
Not sure about the reverse compatibility when its used as the rootstock.