Basically, large objects get supported on the lap, whether you are working with circs, 3+1 x 14" DPN with a Shetland knitting pouch, 4+1 x 18" gansey needles, or 6+1 x 12" Scottish needles.
If you are knitting a gansey or rug for the Queen, then it helps to fold-up the completed work, and hold it together with a few stitches of waste yarn so it is easier to turn, and to keep it from dragging on the floor.
Very large pieces can be hung from a hook on a swivel attached to a belt, at or just below the waist or the bottom of the knitting sheath. Again the object in progress is held in a compact shape with a few stitches of waste yarn. This works for things like shawls and lace table cloths. However, this is awkward, and you may have to adjust the yarn path or or switch to continental knitting, but it does allow working the edge of an object that is several feet in diameter and where the row you are working on contains thousands of stitches. Normally, a modern knitter would think about doing such a object on circs with long cables (tucking the center bulk of the object into a bag to facilitate handling.)
However, DPN with a knitting sheath allow finer and faster knitting, that cannot be sustained on circs. And, the weight of the object hanging from a hook suspended from the bottom of the knitting sheath helps to counter balance the weight of the object on the needles. If museum collections are any guide, then at one time such counter balance devices were fairly common. Of course, if you are just knitting socks, a clew hanging from the bottom of your knitting sheath, will keep your yarn out of the mud as you knit on the quay and counter balance the weight on the needles.
I had better stop. I have written too much about too little.