Doesn't seem to me like there's much point. I know it'll keep it warm all day, tho. I have cooked oatmeal in the steamer, tho. That worked fine. I had to turn it off a little early, otherwise it gets too dry.
I put my rolled (not instant) oats in pot, add boiling water, then put the pot on the burner I used to heat up the kettle. When the burner is cool, the oatmeal is ready. Takes maybe 15 minutes.
Are you thinking of putting it on at night so it's ready in the morning? You could do the kettle thing before hitting the shower and it'll be ready by the time you're done