I found this UFO the other day in a basket I hadn't looked into for a long time. I had finished the main part and was just starting the lacy border when I abandoned it. Thank goodness the sticky note on the chart hadn't moved and I was able to just pick it up and start knitting.
I did the nupps in the way recommended in the pattern (k1, yo, k1, yo, k1 in the same stitch, then purl the 5 sts together on the return row), and they worked just fine. There is another way to do them with a crochet hook all on the right side but I couldn't find the video to remind myself how to do it.
At that time, I found it to be quite a challenge. Now that I have lots more experience knitting lace, it was a fairly easy knit (in spite of the fact I let the green one languish for years before finishing it).
I did however, have one problem. I ran out of yarn before finishing the 'swallowtail' edging and had to bind off 5 rows early. I know I have an extra ball of yarn somewhere and will certainly unpick the bindoff and finish it properly when I do find it.
I recently discovered a crescent swallowtail modification with will be my next shawl project.