As I said before, there are quite some entries already existing in BAT, but with different values.
As an example, in catapults.ini :
-in BAT/JTW :
[RwyCatTrap]
dCatapultOffsetX 1.6
dCatapultOffsetY -20.0
catapultPower 19
catapultPowerJets 25
bSteamCatapult 1
[TrainingCV]
dCatapultOffsetX 17
dCatapultOffsetY -35.0
dCatapultOffsetX2 5.2
dCatapultOffsetY2 -35.0
catapultPower 19
catapultPowerJets 25
bSteamCatapult 1
[OspreyCV]
dCatapultOffsetX 17
dCatapultOffsetY -35.0
dCatapultOffsetX2 5.2
dCatapultOffsetY2 -35.0
catapultPower 19
catapultPowerJets 25
bSteamCatapult 1
and in your pack :
[RwyCatTrap]
dCatapultOffsetX 1.6
dCatapultOffsetY -20.0
catapultPower 10
catapultPowerJets 20
bSteamCatapult 1
[TrainingCV]
dCatapultOffsetX 17
dCatapultOffsetY -35.0
dCatapultOffsetX2 5.2
dCatapultOffsetY2 -35.0
catapultPower 10
catapultPowerJets 20
bSteamCatapult 1
[OspreyCV]
dCatapultOffsetX 17
dCatapultOffsetY -35.0
dCatapultOffsetX2 5.2
dCatapultOffsetY2 -35.0
catapultPower 10
catapultPowerJets 20
bSteamCatapult 1
the difference is in the "catapultPower" and the "catapultPowerJets" lines.
Also find some existing objects from the ships.ini file too, in which I found [RwyTrap], [RwyCatTrap], [TargetRange], [Windsock], [TargetBarge], [TargetSub], [TrainingCV] and [OspreyCV] but I did not check for differences, and probably (but did not watch for now) I will find existing things in chief.ini, stationnary.ini and technics.ini too.
So... what to do (it is an evidence that I will backup the existing files before any modification) ? Overwrite existing parts with your new ones ?