I would look to fit vents at floor level, although the stove is in a box with a flu out the top, the small diameter of the frontiers flu means you can wake up wuth smoke filling the top two thirds of your lavvu. I know this from experiance, when i looked in the stove there were two globs of tar type stuff hanging down from the flu, blocking it sending the smoke through the pot plate on the top. I could see the throuhh draft from the 3 open vents rolling the smoke up towards the open hole in the hat of the lavvu. Cleaning out a hot stove at idiot O'clock in the morning is a very sweary event.
The flu had cooled as the fire died down casing the tar to run back down and solidify instead of being burnt off, blown out the top or being liquid enough to drip back in.
I lost a friend in a 12x12 (due to his own mistake i must add) he closed the bottom of the doors and closed the windows to stop the cold draft, with a kerosene heater running inside, he died all nice and warm in what is normally thought of as a drafty tent to be sleeping.
Dont asume the little gaps in the skirt and doors are good enough.
Ensure that if the stove is burning someone's awake.