Greetings,
I've been playing a local multiplayer server with some friends and we've advanced to just under the steel age. By (un)luck, we haven't found any sort of coal yet despite prospecting far and wide, leaving us to rely solely on charcoal. Obviously this means chopping lods o' trees and sacrificing lods o' flint axes for the firewood to charcoal employment program. We like industry which means we like scale, and the current exchange rate of ONE log to FOUR firewood is frankly abysmal for our needs. It's become a genuine problem; when it's time to refill the charcoal pit, there's a palpable sense of dread at the non-trivial amount of busywork it's going to take to hold LMB on numerous trees, knap numerous axes (because screw wasting durability on firewood), then stack-by-stack turn those numerous log stacks into firewood.
With charcoal being our sole source of metallurgical fuel, we've found ourselves wishing for an improved charcoal-acquiring process, and we've figured that a sawmill would work wonderfully. The basic idea is that a mechanically powered sawmill would receive logs as input, and output firewood with some multiplier. 2x (1 log → 8 firewood) seems good, but 1.5x (1 log → 6 firewood) would be acceptable too. We figure this firewood multiplier would be inherently balanced by the infrastructure necessary to get a sawmill operational; if you can afford to automate iron bloom refining, you oughta be able to streamline your fuel production as well.
Tangentially, the developer's plan to take this game into the steam age, which famously relies upon coal burning to produce the titular steam. If a player were to get lucky like us with their lack of naturally spawning coal, then something like this sawmill idea would help save their temporal sanity when it comes to producing the fuel necessary to power their machinery and metallurgy.
TLDR: Add a mechanically powered sawmill to increase firewood yield from logs so that producing charcoal isn't such a slog at scale.