Yes I suffer from that 555 so now I go to Thailand every 10 weeks to overcome it . Plus it's becoming my second home to be with my wife so I will eventually stop coming back to Australia
My Advice is Make sure she has good ties with Thailand for her to go back . An agent won't change anything in my opinion they won't guarantee an approval when it's pretty much easy to apply yourself . But Iike I said provide everything you can to prove she will go home . .I tried once but failed and she even had a kid and a elderly mother but Australian government don't give a shit that's why I'm going there instead
I suppose if you have a simple TR or visa exempt it would be a straight forward exit . However if you need a re-entry you would have to go old school and see someone