Thanks for this post. The first Zen temple I went to I noticed used a certain sized incense stick that went for 25 minutes. It was the head priests job to watch it. The comment about smell is nonsense, it lingers. A typically Japanese incense stick is about 25 minutes. Maybe 5 inches long.
Also if you sat enough to notice your body will start to go numb at a certain point. My legs go also at around 20-30 minutes so that’s easy lol
