寓守於攻的一些疑問

[90%]

這個問題是在研究藉機流的玩法時想到的問題，有關寓守於攻的啟動時機：

劇透 -   :

Combat Expertise [General]
Prerequisite
Int 13.

Benefit
When you use the attack action or the full attack action in melee, you can take a penalty of as much as –5 on your attack roll and add the same number (+5 or less) as a dodge bonus to your Armor Class. This number may not exceed your base attack bonus. The changes to attack rolls and Armor Class last until your next action.

Normal
A character without the Combat Expertise feat can fight defensively while using the attack or full attack action to take a –4 penalty on attack rolls and gain a +2 dodge bonus to Armor Class.

Special
A fighter may select Combat Expertise as one of his fighter bonus feats.

有關啟動的方式，能否在不是回合內的攻擊動作才啟動專長的效果? EX:藉機攻擊。
因為對比猛力攻擊的原文，寓守於攻沒有在回合一開始決定的說明。

想法是全力攻擊後配合PHB2的羅比拉戰術，藉機攻擊時才調整AB/AC以比較好的防禦羅比拉戰術的劣勢？
另外的應用就是，能否在藉機時把原本回合調整的AB/AC重置成別的量或配置？

[NOKO]

我記得借機攻擊和五尺快步一樣，屬於"不是動作"的動作，不會對應到基於動作的條件上。

所以……