I love your center. Whether you go with the sashing next to the center logs, or on the outside of your first set of braids will be gorgeous. You have brightened up my day with your beautiful quilt. A thought, if you put the sashing next to the 4 center logs, then you can establish a pattern for separating any more borders you want to add. Then you would add another sashing on the outer edge of the flying Geese Braid, etc.