I think this misses the point. Aggressive isn't the one that allows for retreat, that's Conservative, since we stay closer to the doors. We're not guaranteed to be fighting single foes, because the deeper in we are the harder it will be to find respite (and retreat). Getting into traps can reduce the efficacy of Form of Rage by prolonging engagements. More than that, it causes us to lose Arete/an advancement, plus making it harder to find more enemies we're comfortable fighting upon reentry into the Temple due to our tired status. We can go hard once, and I'm not convinced that the admittedly powerful form is versatile and strong enough to plow through each and every novel effect and unknown enemy before retreating. Thus, when we are inevitably forced to retreat, I'd rather avoid the harsh consequences of powering down.