Make sure in your advanced variables that spirit barrage timer is 5 (default like 6000), plus I put this right above the default attacks just to make sure it spams it.
Not clean code, but it works.
if (!UseOOCBuff && !IsCurrentlyAvoiding && !Player.IsIncapacitated)
{
return new TrinityPower(SNOPower.Witchdoctor_SpiritBarrage, 21f, Vector3.Zero, -1, CurrentTarget.ACDGuid, 2, 2, WAIT_FOR_ANIM);
}
// Default attacks
return CombatBase.DefaultPower;