Interestingly I tried pinging an Aussie server and was getting around 291ms. I then connected a vpn via London and I was getting 271ms, so it seems it is possible to knock some off.
Like I said in game, it would seem if you could get a route through Hawaii, you might knock quite a bit off. The vpn "Private internet access" has servers in Honolulu, I wonder if you connected via them if it would route you Sydney > Honolulu > Cali > New York. I would assume this might knock some ms off, but you can only test it and see. The connection isn't guaranteed to be good either.
You can also just try Express or Nord vpn and connect to a bunch of different Sydney servers, and see if it knocks some off. If you could even have roughly the same route you posted, but without the extra Spain hop, it might knock some off. Some of these offer 30 day money back, so can always try, and get a refund if it doesn't work out.
As I said in game, if you try it, best to test with cmd "ping 162.248.95.178" for each different vpn server if you try it, and compare with your current connection.