I just started laughing half tentative half mad cackle when I had the thought:
It might just be worth it to knit a full Pi shawl to NOT have to purl back..
Twice as many stitches but NO PURLING. And, the next thought, calm and wondering - I wonder if this is why EZ perfected the circular shawl? She admitted freely her hate of purling.
Third thought: I wonder if I can steek a Pi and get two halfcircle shawls. One for me, one to gift.
Fourth thought: I am probably way overtired and need to go to bed...