stoic crag
I would like to suggest to shift agriculture research paper modern for later upgrades since it needs a lab powered by electric power there is no chance to obtain it before adv. smelting which is the last advanced tech to be researched.
My suggestion would be to swap it with glass lens which is part of the AU4 recipe right now. As glassworking is available much earlier and also deserves more attention before mechanics.
robust bear
I agree with this but on the other hand i also think Bu4 are too ez to obtain so keeping bu4 for early adv tech could be nice. maybe involving paper milling?
fast herald
Makes sense especially as the current setup means you basically wait forever with AU2s and the go straight to AU4s once adv smelting drops. Also helps spread out the spontaneous massive surge in copper required.
sly bone
These are gated specifically for tech to generally catch up to % reduction