TL;DR
Smelting doesn't scale with ever-increasing mining productivity. It should.What?
A new tier of electric furnace (everything else has tiers that go faster, but furnaces just change fuel type) that has a faster smelting speed and four module slots.Let's call it "Electric Blast Furnace" or "Electric Arc Furnace" and give them crafting speed 2 times that of the Electric Furnace (so that iron smelts at 1.25 per second). The four module slots will help with further scaling.
Why?
As you reach the late-game and possible start pumping science into mining productivity, your mining operations quickly get out of hand (in terms of output), however smelting stacks never scale beyond the electric furnace that's unlocked quite early in the game. So, you are forced to have large and many smelting stacks to accommodate this.It would be nice to have some late-game improvement to smelting. As an additional benefit, this might help with UPS for large bases since smelting quickly ends up being a significant chunk of large bases.
Why not?
One argument against this suggestion could be that it simply moves the goalpost. No higher tier of furnace will ever scale with an infinitely increasing mining productivity. So, there's no reason to arbitrarily add another fixed tier.---
PS: A lot of suggestions tend to have people who reply with "just use mods!". The point of this suggestion is to potentially improve the vanilla experience.