...sawmills?
I bought RW at A7, so never got to play with the things, but happened to see them the other day when I was watching Tynan's earlier RimWorld Alpha videos on YouTube.
Sawmills seemed pretty cool (there were two kinds; manual and electric), allowing wooden walls to be built as logs (stronger but less efficient use of material) or planks (weaker, but makes better use of the wood).
Anyone know why they were removed?
IIRC, it was because Wood and Wood planks was overcomplicating things in his eyes, he wanted to follow the KISS principle, so it was removed rather quickly upon it's introduction to the public arena.
Keep in mind this is just what I remember, Probably not the case and just my shoddy memory playing tricks on me, I think A7 was maybe 2 years ago?
Edit : There is a mod out and about that reintroduces the Wood / Wood planks gimmick, hopefully someone else can point it out for you. *Nudge Nudge*