increase in pull from a filter
I think your mistaken. From a new zorst or cats maybe but not a filter. Also any gains would be negated by the ECU cancelling out any gains and returning the car to stock settings
That is the effect of what the ECU does, but it has no knowledge or ability to measure that it is delivering say 285BHP and correcting it to delivering 276BHp - that's not how it works; fuel, timing and other parameters would be subtly changed and the net effect would be no appreciable loss or gain
And isn't it the ECU thats changing those parameters? Although it's not the ECU directly that is negating the gains but its effect on the components you mention, which indirectly means its the ECU negating the gains?