As far as I'm aware, the intention is that an applicant will be able to take as many sections of the exam at any one time as they wish; the results will be saved in their records. If all sections have been passed within the qualifying period, then a pass in the exam will be recorded.
An applicant will not be able to take the exam unless the system has received a 'sign off as ready' from the ATO.
If this is facilitated correctly, it should ease the administrative burden on ATOs and Examiners and reduce the risk of error delaying licence application. Regarding debriefs, the concept is that the marks obtained for a section will not be saved until the Examiner clicks on the 'debrief complete' window with his examiner account number.
I've no idea whether this will affect 'standalone' FRTOL RTF exams.