Personally I would not hit GA where you plan. Coming thru Alabama, I think the ride thru northern Alabama is much nicer than mid-southern. I pieced together what turned out to be an excellent route IMO on this tour. That said, it is clearly designed based on my start/stop in Atlanta specifically. But this will take you thru the Alabama Bankhead National Forest and surrounding areas which I find to be much more attractive than further south. And it would be a shame to miss the Chief Ladiga and then joining Silver Comet Trail if you're coming this close.

Then for going the rest of the way thru GA it all depends. Are you specifically trying to end the trip where you show? My very first tour, a few years ago, I went to Beaufort SC and took a pretty good ride just using Google Maps bicycle function.