I can only go by my own experience I came in on my temporary visitor visa (I've been here 12 times before during our relationship) and then once in we listed our relationship with births, deaths and marriages officially. So many trips and I've never overstayed anything it was straight forward. Lodged our de facto visa and huge visa payment and they've green lighted my bridging visa. Our Baby born here and we'll of lived together the required 12 months, I'd love to know why they wouldn't allow me permanent residency. If anything I wouldn't be able to leave without my partners permission to take our child as out child is an Austealian citizen with passport. It's not been an easy road but basically for us they want the visa fee and be satisfied we are genuine and that's basically it. You can fake a lot but not 2 years, 12 trips and a baby lol