You can see there that there are stats affected by skills and implants but Activation time / duration remain intact. Is this a skill bug or skill definition error? Is this a skill bug or skill definition error? Or maybe it is not shown in other places but does take an effect (I doubt it, I don’t feel any difference after skilling Shield Operation few times)?
Training the Shield Operation skill does multiple things.
It is a requirement to use shield boosters.
It reduces your passive shield recharge time by 5% per level.
Increasing the skill does not directly make your active defences better, but it allows you to use better shield boosters which can make your active defences better. Increasing the skill does make your passive shield regeneration better.
Seems fair. I found some guides that suggest this skill directly affect shield boosters. Also pyfa is showing higher shield boost with higher Shield Operation. So all of them are wrong.
So if Shield Operation do not affect shield booster recharge per second - is there other skill responsible for that? Armor repair subsystems have Repair Systems skill.
Shield boosting does not change in Pyfa with higher or lower Shield Operation skill. Only the passive shield regeneration value changes. The guide may be wrong.
There is no other skill that affects shield boosters, like there is for armour. But shields are unique in that they have shield boost amplifiers, which is something armour ships do not have.