Yeah. The formula probably should have been
time = time / max(#*0.75, 1)^0.5
time = time / (#+1)^0.5
Currently real time with one is 29.3%(+29.3%) faster, the second 42.3%(+13%) and the third 50% faster(+7.7%)
That other formula would make the first module the listed (and really 30% lower) time, second 81.6%(+18.4%), and third 66.6(+15%). Could actually make a third module on Hiig an actual potential build, but probably not. At least it’d make it more of a thought instead of +7.7% being obviously not worth it.
Even if they didn’t want a second module to give so much, there’s better ways to achieve that and keep the time listed correct for 1 module.
Then they could have listed nice round numbers in the tooltip for 1 module times, that lower with more modules. Instead you get these odd numbers for a single module and they aren’t even listed in game.
It seems like HW2 is full of lessons of what not to do. Even if, yes, the end result of its gameplay winds up to be fairly nice in many areas, don’t get me wrong. The under-the-hood things are really odd.