The term "sketch" implies something done rather quickly, doesn't it? Nothing, however, in knitting is done quickly—at least by me.
This is something I've been ruminating on for a very long time, a graduated, modified Pi shawl. I have never been totally sold on the Pi shawl in actual execution, however brilliant the concept. It's just that when you double the number of stitches from one segment to another, you can end up with "tortured" stitches, overly stretched in the rows before the increase and bunched up immediately after. My trial solution was to make tiny gussets in the transitions areas.
At the top is a 'skeleton' chart for a true Pi shawl (one of six segments shown). To the right is what I have knit up in the photo above. Bottom, a version with larger gussets, which I have not tested yet. For the record, this could work. But it might not be worth the tinkering around, trying to get the patterns to line up.
The yarn is a single ply vintage rustic wool which I have about 8 pounds of in various natural colors. It's pretty rough for a finished shawl, but it's excellent for test knitting, as I paid about a dollar a pound for it.