For now that is what i found, 2 stone wall "basic stone walls" this one is part of the gate tech, and "stone wall" this one is part of the gate and the science pack, and the same thing happen for the electric drill one for the science pack and the other only for the "drill progression".
in the same category of duplicate there is a lot of recipes that when you look into the factoriopedia a lot of recipes is been unlocked in more than one tech: "steel science 1" and "steel science 4" have the same 2 recipes (the 2 firsts) a lot of sulfur tech have duplicate too.
btw im playing in the same save before the last update and the "steam power" tech that was need to build power poles before, now it still show on some of the tech tree but doenst seen to be part of it (you cant click on it to start the research, and it says "hidden-steam-power" with some debug options)
