First comment. It is not optimal to have to rely on another module or especially another exention to work.
Sencond. Lets talk power attack:
https://www.d20pfsrd.com/feats/comba...attack-combat/
You damage bonus on this effect is not correct. Power attack adds -1 attack and +2 damage for every attack. This increases to +3 damage when using a natural weapon that adds 1.5 str bonus to strenght. This is only applicable to monsters that has only one natural attack.
The damage bonus is only +1 on secondary natural attacks.
This causes a big problem automating this, or making an effect here. Some creatures like the "Gorgon" has 1 primary and 2 secondary attacks. Which means no power attack effect will be correct.
There is no good way of doing this, maybe a effect like:
Power attack add manually 6 damage for primary and 3 damage for secondary; ATK: -3 (duration 1 round)
That effect name at least reminds you of doing it.
Third point: The power attack for most creautres I have seen is set up with ATK: +x; DMG: +3x, where it should in most cases be ATK: +x; DMG: +2x, see rules above.
The last point is worse in some ways, but I totally understand why you set it up this way. It is really easy to misunderstand this.
So power attack gives an attack penalty and an CMB penalty.
The effect ATK in fantasy grounds gives an modifier to attack rolls. Since CMB is an attack roll the ATK modifier also applies to CMB rolls.
You power attack effects have: ATK: -x; CMB: -x, which means that the penalty to CMB is doubled. It should only be; ATK: -x