That is incorrect. Percentage loss CANNOT be compared to a flat loss (AKA OP cost increase).
And about balance...
It can and i will...
What does the decrease in Flux dissipation do?
I need to spend more
OP on Flux vents, to even out the flux dissipation and "make up" for the losses
Or, i can't use certain weapons anymore because they produce too much flux for the reduced dissipation rate and have to switch to weaker guns
What does Change in OP do?
You can't spend as many Points on Flux vent's because you don't have that much points (resulting in reduced flux dissipation)
Or, you run out of points to Mount Big/good guns and have to mount weaker guns/cheaper ones
Y did we get the %age based nerf?
Because the OP of a ship mainly depend on the amount of Mount's it has, it will atleast have enough OP that you can mount a properly sized weapon in each slot
A increase in OP cost would've impacted the ships with less Mounts/OP more than other ships
The %age based nerf aims at the Flux dissipation Rate, this usually goes up the more "high tech" ships get...
theese "high tech ships" are generally very fast to begin with and should benefit less from this mod
However, the "older" ships, relying on ballistic mount and armor to protect themself benefit more
Especially the Hound!
I think this is the reasoning behind this choice