Even these needles are so monstrous that none of my stitch markers fit. I'm using cabone rings instead. I bought a package of cabone rings in the last millennium (I dimly recollect it was for crocheted buttons) and haven't used it up yet. It may well be a lifetime supply.
I'm loving the sweater, but... with the smaller (comparatively) needles, I worry that the burn rate is too high. Oh gah. The sweater is shaping to be another round in the epic struggle, Jersey Knitter versus the Not Enough Yarn Banshee.