It's really unclear actually. I've asked my L and I'm yet to get an answer. I've read a couple of cases where things have gone awry for, say, a woman who was a stay at home mum, and who wanted a better settlement after dragging her heels. She didn't get it.
I've also read that the fact there was no property settlement allowed a divorced XH to swoop in on his XW's superannuation fund years and years after agreeing he wouldn't.
I suspect it's just a chance for a free-for-all - especially for the lawyers.