On my 22.5 WSM using the factory ring, I use a full load with a half chimney lit on top.
When I use my 12 inch ring for shorter cooks, I use a full ring with 1/3 of a chimney lit.
To light, I use 2 loosely wadded paper towels doused with some veggy oil. Sit the chimney on top of the towels after lighting.
I can cook at anywhere from 220 to 340 or so using this method and my guru. If I were to have to manually open and close the dampers, it would be far more difficult. BTW, I always cook with the top vent wide open.
Large ring gives me at least 16 hours consistant, and the smaller ring gives me about 8 hours before it starts to fall off. I only use Kingsford Blue for heat, and large chunks for smoke.
The WSM 22.5 is a very forgiving smoker compared to other much cheaper made smokers. Well worth the price difference just in ease of use, nevermind the quality of the product and the warranty. Best move that I ever made. Been cooking on a Bandera for more than a decade, and although I got really good with it, it was a genuine PITA to use for long cooks. I use a foiled water pan with a 16 inch foiled clay saucer. Recovery time from taking the lid off is almost instantaneous.