a good way to balance this would be for each layer to have a different "depth", and for each depth to be investigated.

it would be something like
Logistics-> underground belt deep 1 -> underground belt deep 2 etc
-> logistics 2 -> fast underground belt deep 1 -> fast underground belt deep 2 etc
-> logistics 3 -> express underground belt deep 1 -> express underground belt deep 2 etc

in this way, having 4 underground belts would be less expensive than having 3 fast underground belts

That is a very good idea! I'll see to it that I implement this^^
any suggestions for the amount of science packs needed?

Another idea, as we talk about depth, use the iron axe and the steel axe in the recipes for depth 1 and 2 respectively.

about the amount of science pack, an increase over the previous technology for each level would be fine

Logistics (x1 20 network) -> underground belt deep 1 (x2 40 network) -> underground belt deep 2 (x3 120 network) etc

-> logistics 2 (x1 200 red 200 green) -> fast underground belt deep 1 (x1.5 300 red 300 green) -> fast underground belt deep 2 (x2 600 red 600 green) etc

-> logistics 3 (x1 300 network 300 green 300 blue 300 production) -> express underground belt deep 1 (x1,2 375 red 375 green 375 blue 375 production) -> express underground belt deep 2 (x1.5 450 red 450 green 450 blue 450 production) etc

reduce the value of increase between each level because ... otherwise it's too high and it would be worth the effort with respect to using logistic robots.

reduce the value of increase between each level because ... otherwise it's too high and it would be worth the effort with respect to using logistic robots.

To be honest I dislike the use of logistics robots. That's why I'm making this mod.

As for the amount of science packs I think what you wrote looks fair but maybe it should be a bit exponential in growths.

Another idea, as we talk about depth, use the iron axe and the steel axe in the recipes for depth 1 and 2 respectively.

I was thinking about that. I don't want to make the recipe to be just a free exchange like it is now. Axes are a good idea to use but maybe it should include some iron plates and later even steel too, probably some concrete.

To be honest I dislike the use of logistics robots. That's why I'm making this mod.

me too

As for the amount of science packs I think what you wrote looks fair but maybe it should be a bit exponential in growths.

It's your mod

Another idea, as we talk about depth, use the iron axe and the steel axe in the recipes for depth 1 and 2 respectively.

I was thinking about that. I don't want to make the recipe to be just a free exchange like it is now. Axes are a good idea to use but maybe it should include some iron plates and later even steel too, probably some concrete.

that's exactly what I'm trying to say

Ah, great then^^ I'm bad at communication and I don't want to step on anybodys toe accidentily XD