I have just over 141K miles on my 2009 with AFM still on, and I had #7 plug foul on me a few months ago. I just topped off my oil using 1 qt after 3754 miles, which GM does not consider "excessive".
I'm outside the warranty period so I suppose I just have to live with it or replace it...but I'm not needing another payment right now. Not certain if the Range AFM Delete will help at this point.