I don't know if you are asking for additional help on that staggered seam. I can't offer much except my first experience yesterday (talk about fresh in the memory! But beware my novice level!!) I ended up having to unseam one shoulder because I wasn't careful enough as I seamed...
What I found I needed to do was be very careful in finding the correct (close to the edge) inner stitch bar to pick up. I needed to do what seemed to be a little counter-intuitive vs. keeping a straight line.
Well... good luck to us! :happydance: