As mentioned above L&F has no experience with line shrinkage on Aurora II kites however here is what was found with Flysurf models from Psycho I to Speed III.
First our Psycho I kites from 2001 are still functional.
Respect kite line shrinkage - this line shrinkage is allowed to progress until the kite begins to show poor flying characteristics. The greatest shrinkage is normally the trailing edge lines usually labeled z or br.
For kites in the 15 meter range or greater, a trailing edge line shrinkage in the 8cm or greater usually requires a complete line audit and restoring to factory setting of ALL lines using larkshead extensions. Once done the kite has never had to undergo another line audit. Stretching the lines is not suggested as the lines quickly shrink again. For smaller kites the amount of shrinkage that can occur before the wing profile is compromised is proportionally smaller.
Currently our data shows approx 1cm per year shrinkage which for large kites slows when the lines approach 10cm.
Your kite is less then two years old hence line shrinkage should be small. A complete line audit may not be required.
Our 8 meter Aurora II kites did not fly at all when they arrived from the factory. However the excellent work of PugetSoundKiter at the below listed link solved our problems. See:
Pansh - What to check on arrival
Our kites has two distinct problems.
1. The leading edge was tucking down on one side and the kite would go into a violent spin. The suggestions provided by PugetSoundKiter solved this.
2, The tips were folding in. This was solved by insuring the center and steering lines were the same length and adjusting the depower system length.
You can reduce the drag and increase the turn rate and flying speed by removing the 5th line from the bottom center of the kite and reattaching it half way up one of the the center lines. All our Pulse I and II kites flew much better when the 5th line was moded to a center line instead. See the Flysurf Speed III line plan for details.