I think we are safe to say that the wheel arch, along with the wheel fitment are badly designed from the factory.
They don't allow anything to be messed with, i'm on a mild drop and it rubbed like crazy, i don't want to imagine people who slam it down like there's no tomorrow.
I would have gladly kept the 20mm at the rear since it looked perfect and they also never gave me any issue, but i switched them to the front after i brought them to 12mm, but at least now it's perfectly flush at the front.
I don't personally like tyres sticking out of the body line.
Honestly man, I had no issues with the all seasons that came from the factory or my winters. I was pretty damn low too. Like the fender in the front was probably 8-10mm below the top of the tire. All my issues began once I just put on these new summer tires a few weeks ago.
If you think this was bad, you should of seen the fenders on the mk6. It wasn't even curved at least. You had to ROLL the fender the minute you lower the car, otherwise the tire would hit the fender and begin to DENT the actual fender. I experienced that on my mk6 GTI. Luckily a buddy was able to heat up the fender and roll out the dent + the fender itself.
This car confused me because I thought the fender was already rolled once I was lowered. It had angle of what appeared to be a rolled fender, but evidently, that is how it comes from factory. So that actually helps in comparison to the mk6. Though yeah, so funny a little screw can then cause all the other problems.