Personally I find it appalling that you can pay for the exit row, then as you paid the trolley dollies can be reluctant to remove you.
ABAs should be selected on checkin, or if it's automated, should ask a series of questions before "it" issues a boarding pass.
I'm surprised CASA has not cracked down on the practice as of yet.
I suppose there is only so many muffins the airlines can sell these days hey!