I think number 4 improves the blast furnace. You could use the console in the game to "research_all_technologies" and then check them through.


##################
### TECH COSTS ###
##################

@tier1cost1 = 500
@tier1cost2 = 750
@tier1cost3 = 1000

@tier2cost1 = 1500
@tier2cost2 = 2000
@tier2cost3 = 2500

@tier3cost1 = 4000
@tier3cost2 = 5000
@tier3cost3 = 6000

@tier4cost1 = 8000
@tier4cost2 = 10000
@tier4cost3 = 12000

@tier5cost1 = 15000
@tier5cost2 = 17500
@tier5cost3 = 20000

####################
### TECH WEIGHTS ###
####################

@tier1weight1 = 100
@tier1weight2 = 95
@tier1weight3 = 90

@tier2weight1 = 85
@tier2weight2 = 75
@tier2weight3 = 70

@tier3weight1 = 65
@tier3weight2 = 60
@tier3weight3 = 50

@tier4weight1 = 45
@tier4weight2 = 40
@tier4weight3 = 35

@tier5weight1 = 30
@tier5weight2 = 25
@tier5weight3 = 20

@ap_technological_ascendancy_rare_tech = 1.5

#Given by mechanicum tradition 3. Enables mechanical knights and titans.
tech_est_mechanical_knights = {
area = engineering
start_tech = no
category = { materials }
tier = 0
weight = 0

weight_modifier = {
modifier = {
factor = 0
}
}

ai_weight = {
factor = 0
}
}

#Enabled by Industry 2
tech_est_industry_2_1 = {
cost = @tier2cost1
area = engineering
tier = 2
is_rare = yes
category = { industry }
#prerequisites = { "tech_basic_industry" }
weight = @tier3weight1

modifier = {
country_minerals_produces_mult = 0.05
}

weight_modifier = {
modifier = {
factor = @ap_technological_ascendancy_rare_tech
has_ascension_perk = ap_technological_ascendancy
}
modifier = {
factor = 1.25
research_leader = {
area = engineering
has_trait = "leader_trait_expertise_industry"
}
}
modifier = {
factor = 0
Not = {
has_tradition = tr_est_industry_2
}
}
}

ai_weight = {
modifier = {
factor = 1.25
research_leader = {
area = engineering
has_trait = "leader_trait_expertise_industry"
}
}
}
}
#Enabled by Industry 2
tech_est_industry_2_2 = {
cost = @tier2cost2
area = engineering
tier = 2
is_rare = yes
category = { industry }
#prerequisites = { "tech_basic_industry" }
weight = @tier3weight2

modifier = {
starbase_shipyard_build_speed_mult = 0.10
}

weight_modifier = {
modifier = {
factor = @ap_technological_ascendancy_rare_tech
has_ascension_perk = ap_technological_ascendancy
}
modifier = {
factor = 1.25
research_leader = {
area = engineering
has_trait = "leader_trait_expertise_industry"
}
}
modifier = {
factor = 0
Not = {
has_tradition = tr_est_industry_2
}
}
}

ai_weight = {
modifier = {
factor = 1.25
research_leader = {
area = engineering
has_trait = "leader_trait_expertise_industry"
}
}
}
}
#Enabled by Industry 2
tech_est_industry_2_3 = {
cost = @tier3cost2
area = engineering
tier = 3
is_rare = yes
category = { industry }
#prerequisites = { "tech_basic_industry" }
weight = @tier4weight2

modifier = {
shipclass_mining_station_build_cost_mult = -0.20
}

weight_modifier = {
modifier = {
factor = @ap_technological_ascendancy_rare_tech
has_ascension_perk = ap_technological_ascendancy
}
modifier = {
factor = 1.25
research_leader = {
area = engineering
has_trait = "leader_trait_expertise_industry"
}
}
modifier = {
factor = 0
Not = {
has_tradition = tr_est_industry_2
}
}
}

ai_weight = {
modifier = {
factor = 1.25
research_leader = {
area = engineering
has_trait = "leader_trait_expertise_industry"
}
}
}
}
#Enabled by Industry 2
tech_est_industry_2_4 = {
cost = @tier3cost3
area = engineering
tier = 3
is_rare = yes
category = { industry }
#prerequisites = { "tech_basic_industry" }
weight = @tier4weight3

prereqfor_desc = {
hide_prereq_for_desc = component
custom = {
title = "tech_est_industry_2_4_effect_title"
desc = "tech_est_industry_2_4_effect_desc"
}
}

weight_modifier = {
modifier = {
factor = @ap_technological_ascendancy_rare_tech
has_ascension_perk = ap_technological_ascendancy
}
modifier = {
factor = 1.25
research_leader = {
area = engineering
has_trait = "leader_trait_expertise_industry"
}
}
modifier = {
factor = 0
Not = {
has_tradition = tr_est_industry_2
}
}
modifier = {
factor = 0
Not = {
has_tradition = tr_est_industry_4
}
}
}

ai_weight = {
modifier = {
factor = 1.25
research_leader = {
area = engineering
has_trait = "leader_trait_expertise_industry"
}
}
}
}
#Enabled by Industry 2
tech_est_industry_2_5 = {
cost = @tier4cost2
area = engineering
tier = 4
is_rare = yes
category = { industry }
#prerequisites = { "tech_basic_industry" }
weight = @tier5weight2

modifier = {
planet_miners_rare_crystals_produces_mult = 0.20
}

weight_modifier = {
modifier = {
factor = @ap_technological_ascendancy_rare_tech
has_ascension_perk = ap_technological_ascendancy
}
modifier = {
factor = 1.25
research_leader = {
area = engineering
has_trait = "leader_trait_expertise_industry"
}
}
modifier = {
factor = 0
Not = {
has_tradition = tr_est_industry_2
}
}
}

ai_weight = {
modifier = {
factor = 1.25
research_leader = {
area = engineering
has_trait = "leader_trait_expertise_industry"
}
}
}
}