Frogging the FLAK sleeve

So I decided to frog the sleeve (first picture) back to where I started knitting in the round and knit it flat instead, and add a few more cables while I was at it, laddering back to the start of the sleeve. The problems: first, no matter what I did, knitting it with dpns or a 16" cable needle or my aborted attempts at magic loop, my hands didn't like it; and second, I was bored silly with all that seed stitch. I think it'll go faster this time, knitting flat. Sounds contradictory -- I usually go pretty fast knitting in the round on dpnsd when knitting socks -- but if my hands aren't protesting, I ought to get up to speed pretty quickly.