the visa is valid for 6 months arrive get 60 plus 30. Depart come back get another 60 plus 30. Then if you leave and come back into Thailand the day before it expires you get 60 days plus 30 day extension. Hence nearly 9 months
OK so beware of the 30 day extension plus 60 for thai family does not take you past the 3 months Chris hate to see you loose it after the pain to get it.
Sydney has always been easier to deal with over the past years I have used them for many visa applications. Evisa will be interesting to see as only NSW people can use Sydney from the 19th