The ratio doesn't work for steel, the more complicated process yields far less.

360 iron ingot will make 800 iron plate, this would cook to 180 steel.
For smelting:
360 iron ingot -> 36 steel ingot -> 5.4 molten -> 27 steel.
Even counting the other ingots as free for the adv molten would at best yield 81 steel.

The rest all appear to follow the rule: More complicated = more plate from ore

What other mods are you using? Are you on the most recent version of the mod?

According to my calculations, we have the 3 early game smelting routes:

(No angels)
5 iron ore -> 12.5 iron plate -> 1.04 steel plate
0.21 steel plate per iron ore

(Angels iron)
48 iron ore -> 240 iron ingot -> 48 molten iron -> 133 iron plate -> 11.1 steel
0.23 steel plate per iron ore

(Angels iron + steel)
48 iron ore -> 240 iron ingot -> 80 steel ingot -> 12 molten steel -> 13.3 steel
0.27 steel plate per iron ore

Something is screwy then, my install has recipes as follows:

(Furnace)
2 iron ore -> 20 iron plate
40 iron plate -> 9 steel plate

(Angel smelt)
48 iron ore -> 240 iron ingot
60 iron ingot -> 12 molten iron
3.6 molten -> 40 iron plate

120 iron ingot + 6 oxy -> 12 steel ingot
80 steel ingot -> 12 molten steel
3.6 molten steel -> 18 steel plate

In addition to all angels and bobs (latest) and 0.1.37 marathomaton, I have a fair number of other mods. Rather than posting 70 mod names, I'm going to play the enable/disable game and see if I can get your numbers. I'll reply to this with my findings.

I had two issues:

1> I had the flag for cheap steel set in bobconfig/config.lua. Took some time to remember that existed.

2> Research revolution 0.14.11 screws with a lot of recipes, confusing since the latest update says "14.11 Support Auto Marathon mod".

Regardless, since this appears to be an issue with another mod I'll just not use it. Going to just start another game and see how a steam engine that doesn't take 5000 iron feels to craft.

I do greatly appreciate both the mod and the incredibly quick responses from you, thank you.

Thanks for the feedback!

Regarding 1>, this mod actually force disables bob.CheaperSteel unless you unspecify it in THIS config.

Regarding 2>, I'm pretty sure it's not research rev as it shouldn't touch non-science related recipes.

Regarding your recipes, the only buggy one is this one:

"120 iron ingot + 6 oxy -> 12 steel ingot"

Some mod comes in after mine and changes it. This should be 40 steel ingots output, which fixes all the ratios.

The part where iron plate is 10x exploded instead of 2.5x, and steel is 4.5x exploded instead of 1x, is some thing i can fix.

Regarding 1 again>
Cheapsteel in bob is set as true and in unzipped file. The cheapsteel override in marathon doesn't have any effect when:
True as zipped file
True as unzipped file
False as unzipped file

Anything you want me to try? It appears to be nonfunctional for me.

Regarding 2> You are correct, it wasn't ResRev. Recipes are fine without it, but if I add it back and remove OrbitalIonCannon, recipes remain fine. Add both and recipes do the x10 thing. Leave them both and remove ShinyBobs and everything is fine again. I'm at a loss on how to determine what is actually happening. The x10 thing carries into many recipes (copper wire taking 40 copper plates) but 1.38 solves everything so .. hooray? Yes, Hooray!

The steel ingot recipe problem was tied to the cheap.steel flag and fixed by changing the flag.

Hello. Did you figure out which mod screwed the ratios? Because right now, my Angels shows me : 80x iron ingot + 60 oxygen gas = 6x Steel ingot.

It means that to make 1 steel ingot I will need 160 iron ore at level 1 angels smelting. But if I skip Angels completely and just smelt directly iron ore in steel furnaces, I will get 1 steel for 75 iron ore. That means the angels takes more than 50% efficiency. That does not seems right.