Are you sure that's the 208V amps and not the 240V ratings -- a 5 KW range rated for 240V will not draw 5 KW at at 208V, it will draw less.
If the user happened to turn on every burner and the oven, those elements still cycle fairly soon. So it won't be drawing a full 50A for very long. That's why the demand factor is there, no matter what you do these burners cycle.
Thank Bob
grate article.
I do have a job that requires 1 wall oven rated 20.8 amp and 1 cook top rated 30.1 amp @208 Volt
if I add them together without the demand I will not have sufficient feeder to the apartment 60 Amp.
If I calculate with the demand It will work but in reality when the customer will turn them both on
I don't think the main will hold.