So, I added a fake type of Ceramic, Greenware (which is real life unfired clay), I copypasted its parameters from Earthenware, with a value of 1 and a density slightly lower than clay's, and modded all clays but Kaolinite and Fire Clay to become Greenware, instead of Earthenware, when processed at the Kiln. For now, I've just edited the Kiln's reactions not to use fuel, renamed them from "make" to "shape", and gave a 20% chance for every shape reaction to fail. I didn't make a reaction to fire Greenware yet.
This is the current term plan:
A Potter's Workshop, which will be low-tech and have the shaping reactions that now are in the Kiln.
A Potter's Wheel, which will require surely mechanism and maybe something else I'll think of. It'll have no chance/a lower chance to fail, or maybe make more items at once.
The Firepit we already have will be used to fire Greenware items to Earthenware items, we'll decide if it's possible to use firewood as fuel or if only charcoal may works.
Really, what's the max burning temperature for firewood?