My '09 C6Z scrapes on EVERYTHING, and it didn't do that when I got it 5 years ago, so I think it's a settling thing. That's the primary reason I got the front end lift on my 2021. Having said that, the only thing you're scraping is the vertical portion of the lower valence. They are cheap and easy to replace. The ride height can be adjusted, but I don't know how to do it. I'd vote for grab a few spare lower valences, keep them in stock, and call it a day. Enjoy your car.
I do agree with Norm, it could be a shock thing...but, my '09 only has 38k, shocks should NOT be an issue.