According to the description in the menu, the Targeting Control Systems perk should decrease target lock-on time by 15% at rank 2, 30% at rank 3, and 60% at rank 4.
What it actually does is decrease the lock-on time by 15% at rank 2, 15% at rank 3, and 30% at rank 4.
I have simply changed the abFortifyTargetLockTime magnitude to 0.3 in abTargetingControlSystems_TargetLockTime_02 [SPEL: 002CCF94], and changed it to 0.6 in abTargetingControlSystems_TargetLockTime_03 [SPEL: 002CCF95]. These spells are only ever referenced by this perk, so changing these values does nothing except fix this issue.
1.9.51.0
English (EN)
Yes
Take rank 2 of the targeting control systems perk. Select your ship in the command console, and use getav spaceshiptargetlocktime. The value should return 2.55, representing a 15% decrease from the base 3.00 value.
Then, take rank 3 of the perk. It will still return 2.55, instead of the expected 30% decrease to 2.1.
Then take rank 4, and you will now see 2.1 instead of the expected 1.2.