My dog does an informal down-stay in kitchen for 20-30 minutes every night when I am making dinner. He would always come over and hover when he smelled food, so if he laid down instead of standing near me, I would give him a little tidbit and say "Good!" (at random intervals, like whenever I would glance over). I did not really care, but I didn't want him to get in the habit of standing behind me all the time. Now it seems that he has a habit of the long downstay, and it is "finished" when I put down his bowl. We humans eat dinner too, then.
Could he do this on an obedience field? No!
But I don't care, I just like that he stays out of the way while I"m cooking and I don't have to worry about tripping over him while carrying a hot pan.