As someone who is not capable of affording or building a metal retort, I am loving the pit method. It may not be perfect, but I have some biochar instead of nothing, and over time any imperfections will balance out as seen in old sites.
I save all prunings until the fall, nothing larger than 3 inches diameter, and burn it by feeding it to the fire in increments, not allowing the flames to die down. When all is burned I quench it thoroughly with water, so not too much ash, and hopefully the water wash will help lower the higher ph.
I mix it with the chicken bedding and then mulch with that. Not the best method for incorporating it, but it eventually gets there. I think the most valuable aspect of it is not a fast bump, I have good fertility already, but down the road I hope to be able maintain high levels with less amendments. What could be better than creating long term fertility based on microbial activity? And that isn't even touching the carbon sequestration part.