I dont think there is anything wrong with rolling the fenders when done correctly. Had mine rolled when I was running my Camaro wheels. Im lowered on h&r springs and only rolled from the 10 oclock to 2 oclock position. Didnt hafta flatten the inner lip either. Minimal rolling did the job for me.
But, of course, you do what you feel most comfortable doing. Seems like milling would be too expensive.