Well, I didn't like my Flex DA with 7.5" curved CCS pads and I made sure those were centered. I'd guess the 6" Edge pads, whatever style, would work best.
Most experienced detailers, me NOT being one of them, will tell you they've gotten better correction with smaller diameter pads, whether it be rotary or DA, or so I've read.
I don't see the Edge Flex adapter changing that. If anything it finally allows the use of smaller pads for the hard to reach areas.