My rainbow spiral blanket is finished!
I had to undo the first border I did, as you can see below, the original edging is all curling up on itself. As I was working it, I was telling myself not to worry, that blocking would soon straighten it out but by the penultimate row, it was clear that nothing short of steamrollering it would make it lay flat.
This time, I worked up a design on a small scale rather than just "diving in", the swatch I made laid flat and so here is a close up of the new border it as it was being blocked. On the previous version I'd gone round the post of the row underneath to give some interest. This time I just used a double crochet (UK terminology) spike stitch into an intermediary black row.
If you're interested in me writing up the pattern explaining how I did it, contact me through my Ravelry account (SoozJewels) or leave a comment below. If there's demand, I'd be happy to do so!