I hear the Australian Government Design Regulations are going to change to require all Australian versions of the Morgan to have a Jarrah frame
Jarrah (or swan river mahogany as they used to call it in colonial times) would be no good for that purpose - it's too hard and tight grained. For body framing you need something with a bit of flex to it.
The floor of my pub is of Jarrah. Very robust and hard wearing it is too.
p.s. You beat me to it Richard !!