...so, earlier I made a modded metal and its alloy. They worked.
(the reaction class "fel_flux" tag i added to some rarer non-economic rocks)
[REACTION:FEL_STEEL_MAKING]
[NAME:make felsteel bars]
[BUILDING:SMELTER:NONE]
[REAGENT:A:150:BAR:NO_SUBTYPE:METAL:FEL_IRON]
[REAGENT:B:1:BOULDER:NO_SUBTYPE:NONE:NONE][REACTION_CLASS:FEL_FLUX]
[REAGENT:C:150:BAR:NO_SUBTYPE:COAL:NO_MATGLOSS]
[PRODUCT:100:1:BAR:NO_SUBTYPE:METAL:FEL_STEEL][PRODUCT_DIMENSION:150]
[FUEL]
[SKILL:SMELT]
Today I decided to make some more (because otherwise fighting the critters I also modded would be too much fun).
[INORGANIC:SARONITE]
weak on its own, needs to be smelted into sarsteel
[USE_MATERIAL_TEMPLATE:METAL_TEMPLATE]
[STATE_NAME:SOLID:saronite]
[STATE_NAME:SOLID_POWDER:saronite dust]
[STATE_ADJ:ALL_SOLID:saronite]
[STATE_NAME_ADJ:LIQUID:molten saronite]
[STATE_NAME_ADJ:GAS:boiling saronite]
[DISPLAY_COLOR:3:0:1]
[MATERIAL_VALUE:45]
[SPEC_HEAT:129]
[MELTING_POINT:11300]
[BOILING_POINT:13141]
[SOLID_DENSITY:19320]
[LIQUID_DENSITY:17310]
[MOLAR_MASS:55845]
[IMPACT_YIELD:175000]
[IMPACT_FRACTURE:350000]
[IMPACT_STRAIN_AT_YIELD:47]
[COMPRESSIVE_YIELD:175000]
[COMPRESSIVE_FRACTURE:350000]
[COMPRESSIVE_STRAIN_AT_YIELD:57]
[TENSILE_YIELD:50000]
[TENSILE_FRACTURE:100000]
[TENSILE_STRAIN_AT_YIELD:34]
[TORSION_YIELD:50000]
[TORSION_FRACTURE:100000]
[TORSION_STRAIN_AT_YIELD:145]
[SHEAR_YIELD:50000]
[SHEAR_FRACTURE:100000]
[SHEAR_STRAIN_AT_YIELD:145]
[BENDING_YIELD:50000]
[BENDING_FRACTURE:100000]
[BENDING_STRAIN_AT_YIELD:44]
[MAX_EDGE:10000]
[ITEMS_HARD]
[ITEMS_METAL]
[ITEMS_BARRED]
[ITEMS_SCALED]
[INORGANIC:SARONITE_STEEL]
[USE_MATERIAL_TEMPLATE:METAL_TEMPLATE]
[STATE_NAME_ADJ:ALL_SOLID:saronite steel]
[STATE_NAME_ADJ:LIQUID:molten saronite steel]
[STATE_NAME_ADJ:GAS:boiling saronite steel]
[DISPLAY_COLOR:1:7:1]
[MATERIAL_VALUE:40]
[SPEC_HEAT:500]
[MELTING_POINT:16000]
[BOILING_POINT:18500]
[ITEMS_WEAPON][ITEMS_WEAPON_RANGED][ITEMS_AMMO][ITEMS_DIGGER][ITEMS_ARMOR][ITEMS_ANVIL]
[SOLID_DENSITY:9900]
[LIQUID_DENSITY:7500]
[MOLAR_MASS:60845]
[IMPACT_YIELD:2205000]
[IMPACT_FRACTURE:3320000]
[IMPACT_STRAIN_AT_YIELD:1050]
[COMPRESSIVE_YIELD:2205000]
[COMPRESSIVE_FRACTURE:3320000]
[COMPRESSIVE_STRAIN_AT_YIELD:1050] 160
[TENSILE_YIELD:530000]
[TENSILE_FRACTURE:800000]
[TENSILE_STRAIN_AT_YIELD:250] 200
[TORSION_YIELD:500000]
[TORSION_FRACTURE:780000]
[TORSION_STRAIN_AT_YIELD:250]
[SHEAR_YIELD:500000]
[SHEAR_FRACTURE:800000]
[SHEAR_STRAIN_AT_YIELD:250] no data, used 200
[BENDING_YIELD:500000]
[BENDING_FRACTURE:790000]
[BENDING_STRAIN_AT_YIELD:250]
[MAX_EDGE:10000]
[ITEMS_HARD]
[ITEMS_METAL]
[ITEMS_BARRED]
[ITEMS_SCALED]
...and just to have some more colors in the fort
[INORGANIC:NETHER_ELECTRUM]
[USE_MATERIAL_TEMPLATE:METAL_TEMPLATE]
[STATE_NAME_ADJ:ALL_SOLID:nether electrum]
[STATE_NAME_ADJ:LIQUID:molten nether electrum]
[STATE_NAME_ADJ:GAS:boiling nether electrum]
[DISPLAY_COLOR:5:5:1]
[MATERIAL_VALUE:25]
[SPEC_HEAT:180]
[MELTING_POINT:13828]
[BOILING_POINT:16968]
[SOLID_DENSITY:15000]
[LIQUID_DENSITY:13000]
[MOLAR_MASS:140000]
[IMPACT_YIELD:185000]
[IMPACT_FRACTURE:360000]
[IMPACT_STRAIN_AT_YIELD:120]
[COMPRESSIVE_YIELD:185000]
[COMPRESSIVE_FRACTURE:360000]
[COMPRESSIVE_STRAIN_AT_YIELD:120]
[TENSILE_YIELD:60000]
[TENSILE_FRACTURE:110000]
[TENSILE_STRAIN_AT_YIELD:80]
[TORSION_YIELD:60000]
[TORSION_FRACTURE:120000]
[TORSION_STRAIN_AT_YIELD:195]
[SHEAR_YIELD:60000]
[SHEAR_FRACTURE:110000]
[SHEAR_STRAIN_AT_YIELD:195]
[BENDING_YIELD:60000]
[BENDING_FRACTURE:110000]
[BENDING_STRAIN_AT_YIELD:80]
[MAX_EDGE:10000]
[ITEMS_HARD]
[ITEMS_METAL]
[ITEMS_BARRED]
[ITEMS_SCALED]
[INORGANIC:ELDER_ELECTRUM]
[USE_MATERIAL_TEMPLATE:METAL_TEMPLATE]
[STATE_NAME_ADJ:ALL_SOLID:elder electrum]
[STATE_NAME_ADJ:LIQUID:molten elder electrum]
[STATE_NAME_ADJ:GAS:boiling elder electrum]
[DISPLAY_COLOR:4:4:1]
[MATERIAL_VALUE:30]
[SPEC_HEAT:180]
[MELTING_POINT:15828]
[BOILING_POINT:17968]
[SOLID_DENSITY:20000]
[LIQUID_DENSITY:15000]
[MOLAR_MASS:160000]
[IMPACT_YIELD:205000]
[IMPACT_FRACTURE:400000]
[IMPACT_STRAIN_AT_YIELD:150]
[COMPRESSIVE_YIELD:205000]
[COMPRESSIVE_FRACTURE:400000]
[COMPRESSIVE_STRAIN_AT_YIELD:150]
[TENSILE_YIELD:100000]
[TENSILE_FRACTURE:150000]
[TENSILE_STRAIN_AT_YIELD:100]
[TORSION_YIELD:100000]
[TORSION_FRACTURE:150000]
[TORSION_STRAIN_AT_YIELD:215]
[SHEAR_YIELD:100000]
[SHEAR_FRACTURE:150000]
[SHEAR_STRAIN_AT_YIELD:215]
[BENDING_YIELD:80000]
[BENDING_FRACTURE:150000]
[BENDING_STRAIN_AT_YIELD:100]
[MAX_EDGE:10000]
[ITEMS_HARD]
[ITEMS_METAL]
[ITEMS_BARRED]
[ITEMS_SCALED]
[REACTION:SARONITE_STEEL_MAKING]
[NAME:make saronite steel bars]
[BUILDING:SMELTER:NONE]
[REAGENT:A:300:BAR:NO_SUBTYPE:METAL:FEL_IRON]
[REAGENT:B:150:BAR:NO_SUBTYPE:METAL:SARONITE]
[REAGENT:C:1:BOULDER:NO_SUBTYPE:NONE:NONE][REACTION_CLASS:FEL_FLUX]
[REAGENT:D:150:BAR:NO_SUBTYPE:COAL:NO_MATGLOSS]
[PRODUCT:100:2:BAR:NO_SUBTYPE:METAL:SARONITE_STEEL][PRODUCT_DIMENSION:150]
[FUEL]
[SKILL:SMELT]
[REACTION:NETHER_ELECTRUM_MAKING]
[NAME:make nether electrum bars]
[BUILDING:SMELTER:NONE]
[REAGENT:A:300:BAR:NO_SUBTYPE:METAL:SILVER]
[REAGENT:B:300:BAR:NO_SUBTYPE:METAL:GOLD]
[REAGENT:C:150:BAR:NO_SUBTYPE:METAL:FEL_IRON]
[PRODUCT:100:5:BAR:NO_SUBTYPE:METAL:NETHER_ELECTRUM][PRODUCT_DIMENSION:150]
[FUEL]
[SKILL:SMELT]
[REACTION:ELDER_ELECTRUM_MAKING]
[NAME:make elder electrum bars]
[BUILDING:SMELTER:NONE]
[REAGENT:A:300:BAR:NO_SUBTYPE:METAL:SILVER]
[REAGENT:B:300:BAR:NO_SUBTYPE:METAL:GOLD]
[REAGENT:C:150:BAR:NO_SUBTYPE:METAL:SARONITE]
[PRODUCT:100:5:BAR:NO_SUBTYPE:METAL:ELDER_ELECTRUM][PRODUCT_DIMENSION:150]
[FUEL]
[SKILL:SMELT]
And these don't work, the smelter doesn't have the new "make ... bars" reaction. I'm sure I defined the metals properly (arena has stuff made of them), I can smelt the modded ore and get saronite bars, but the alloy reactions are nowhere to be found, not even the manager screen.