I cast this one on for an adult cozy blanket. I used US11 -40” circs and double strands of Pound of Love. I went for 40” wide by 64” long. It took 14 pattern repeats. It has a nice squishy wool Irish sweater feel. I do want to make this one again but bigger and single stranded but still on US11 needles for more of a summer weight. Super easy pattern. I would recommend just casting on in 12 stitch increments, skipping the “+1” bs stitch, and making a seed stitch border wider than 3 stitches...it seems to want to fold in with just 3 stitches. This would make a great wedding gift heirloom made with Fishermen’s Wool or an exquisite merino super wash. I would also like to see the pattern in WoolEase Thick and Quick on US15s or even larger for more open work shining through. And lastly, (can you tell I liked this pattern) lace weight or fingering weight on smaller needles would be a gorgeous christening blanket!
As long as you know K2tog, SK2P, SSK and yarn overs...you can do this pattern. I have no idea where the Level 5 - Experienced is coming from for skill level. As a double check, place markers after each 12 stitch repeat and count your stitches on your wrong side purl rows and fudge them up or down one as needed. Any corrective stitches just hide in the lace pattern so don’t sweat it.
Cheers!