Ten TNT duper wood farm

TheySix's ten duper wood farm, a V2 of a bilibili design that he credits. Ten b36 TNT dupers fire at once across a leaf and obsidian frame, with cobblestone generators feeding them and up to 196 hopper minecarts on three rail levels collecting. It handles every tree including the large ones, and it is the biggest tree farm in the library at 239 observers and 129 repeaters. It is also the one whose comment section is most consistently about the tutorial rather than the farm.

• Replace every waterlogged leaf with obsidian. This is the fix for the dupers blowing themselves up, and three separate builders arrive at it independently.
• The stair beside each dispenser on the dupers must not be waterlogged, and there must be no cobblestone in front of it.
• TNT and observer placement is never shown and is the most asked question on the video. The observer looks at the leaf wall from the left piston with the TNT to its right, so the sign stays under the TNT block. TheySix also posted an image of it in the comments.
• If the rails keep connecting between levels, pull every hopper minecart out, lay all the rails for the three levels, then put the carts back.
• Jungle does not work. The branches collide with the obsidian and waterlogged leaves and the TNT destroys itself. Mangrove is out too.
• Do not wear depth strider boots while AFKing, they slow you in the water, and take a world backup before the first run.