The line that lowering an XI will kill your front axles is a freagin MYTH!!!!!!!!!!!!!!! It is a myth passed on by those who have zero first hand experience.
Yes, lowering an XI changes the front axle geometry, but the front axles have inboard and outboard CV joints, thus they are designed for changing geometry applications!!!!
What will happen. When you lower your XI, it will change the load on the CV boot clamps. From factory, these clamps are very poor and are not a good design for sealing the boots. Gone unchecked, your boots will empty of grease and the joint will fail and fanboys will groan that the lowing springs did it. BS!!!!
If you install new boot clamps, preferably the more robust type, not the cheap chinese or even OEM ones, you will be fine. I have 23k miles on my lowered XI and have had zero axle issues.
LOWERING AN XI DOES NOT KILL THE AXLES !!!!!!! POOR CLAMPS ARE TO BLAME!!!