The problem is not so much how low it is but the shape of the front lip, or fowardmost bottom part of the bumper. And thats the problem of the 996 Aerokit/GT3 and seems like even worse in the 997 aerokit. It comes down so much and so much to the tip of the bumper that it really complicates the clearance when arracking an incline. I found this to affect clearance much more than ride height.

The bottom part of the stock bumper of the 997S is angled backward and the chip or lip is placed "under" the bumper, not at the front so I have found that even with the -20mm suspension it has an incredilble clearance, I can go anywere, wereas with my previous 996 with aerokit and -10mm M030 sport suspension I was prohibited from many garages and so on.

The lip on the 997S aerokit/GT3 is even worse and its painted like you say. Though I have seen black plastic ones which may be a good idea to have instead.