I thought about another tier of bucketwheel excavator that represents the new turbo belt. So that we can unlock it after getting to vulcanus.

That is a good idea. I need to think about balancing it.
I've also seen your other thread (https://mods.factorio.com/mod/BigDrills/discussion/6735090fff1d53558e8b6dd9) and considering it as well

Maybe make it so that to mine tungsten we need sulfuric acid like with uranium. And for balancing I would say make them very expensive so that they need materials from vulcanus and fulgora to be crafted?

With the new quality mechanic I would say maybe you could make it possible so that the bucketwheel excavator needs less power?

I wanted to nerf the higher tier excavators.
So I looked through some balancing mechanics:
- Mining fluids are bound to the ore, not the miner -> not possible
- Can't make them too expensive: This woul add weight, and you couldn't place them into a rocket
- Quality effects aren't controlled at the entity, but globally per entity type (mining-drills) -> not possible
- you can decrease power with modules/beacons anyway
- I tried inversing the effect of resource-drain, so that higher Tier drills are faster, but consume the patch faster, but sadly it can't go above 100% (default mining rate)

What I came up with is:
- Added Mk4
- Requires materials & tech from Vulcanus & Fulgora
- Can mine Tungsten
- Has -100% Productivity -> offsets 10 Lvls of mining productivity research or an Epic quality miner
- Has 6 module slots

So do I understand that right that the miner has an inital -100% productivity. When I add productivity modules then I need a total of 110% to at least reach 10% productivity bonus?

The rest is nice and a big thx for your work.