Home affairs will tell you that your form is different and you will have to complete a barely legible copy with missing left-hand-side.
Good idea to fill in your own form though so that you can deduce the missing field headings.
In addition, obtain your parents' ID numbers and place of birth. (which doesn't appear on the online version but you will need complete this)
Fill in your own details for a second time under applicant details.
The queue isn't insane since a different counter than passport/ID will serve you. I could arrive at 7am and finish by 9:30am.