Hey!

The following doesn't block progress at all, it's just a little out of place.
--> The Cobalt steel axe technology is available after both steel axe and brass have been unlocked. However, it takes blue science to make cobalt to actually research it.

Hi,

thanks for your report.

I already read your message and the other discussion too, havent managed to look into it until now, but will probably fix it tomorrow when i have the time.

You're right.
The Cobalt steel axe asks you to craft 50 cobalt steel, but it was unlocked by Brass processing, so it showed up long before you could make cobalt steel.

The cause was an interaction between mods. Bob's mining makes the axe require Cobalt processing. When Angel's Smelting takes over cobalt steel, it swaps Cobalt processing for Brass processing everywhere in the tech tree, and that swap also changed the axe's prerequisite.

This is fixed for the next release (2.1.7): the Cobalt steel axe now requires Cobalt steel smelting 1, so it only becomes available once you can make cobalt steel. I also added an automated check to the mod's tests that catches this kind of mismatch, where a "craft X" technology is available before X can be made, so similar cases shouldn't slip through again.