Ingrid,
I’m not very good at ribbing on dpns. I need more practice.
I was wondering if I could some how get away with knitting the ribbing of a sock on my dpns flat and then working the rest of the sock in the round, and then seaming the ribbing, is that possible?
I think it is.
You could do the ribbing straight, and then keep the stitches open, and then connect it… Then go back after you got it done and seam it.
HTH
I’m not the sock maker in these here parts, but I agree that if you don’t mind a seam, then do it flat to start with. You might want to add a stitch at each end of the ribbing to give you a seam allowance.
I’m gona try it!
I am also pretty bad at seaming ribbing together, Im getting better. HEH Maybe it’ll be a very short rib.
Thanks for the suggestion of extra stitches.
you could maybe do the matress seam that’s here(you have to scroll down to the video). It’s very easy to do. 
Just watch the video and get the hang of it