Does the 3 hour job not produce 3 times the product of the 1 hour job? I.E. Have they deliberately dropped the production at that stage. Which would imply a very deliberate nerf if so. Or a massive saving in time somewhere in the refinery to bring it back to normal.
If it does produce three times the amount you end up at identical costs for characters to start with (Fair enough simplifying character cost maths like that though, and in your particular use case it probably comes out the same margin) and a small start up cost to train the second alt needed.
Also one small error in your maths, you haven’t taken the 20% time saving from skills into account that we already know exists, which drops you down to three characters needed, so it comes out pretty much the same at that point.
@Querns Well, the maths has to be done from somewhere, & given it seems an in game (obviously dev server) screenshot, why shouldn’t the maths come from there. That said, even that maths seems to be coming out at about break even to current costs in this particular scenario, and the more you can put it on characters/alts that already exist for other reasons the better off you are compared to present.