When raging, HP increases from a boosted CON aren’t lost first. If the barbarian falls in a fight, when the rage is done that can mean that the barbarian suffers instant death.

Obviously the developers fixed this issue with the unchained version, but I’m not a fan of how they removed the STR aspect of the rage and made it a static bonus to attack/damage instead. That’s not what this question is about, so answers should not include a reference to the unchained option.

What is the most optimal way to utilize the HP boost from the raging CON?

Is it not best to simply ignore the extra HP, and play as if it wasn’t there, to keep your character out of trouble? I’ve seen people recommend the feat Raging Vitality, but that only seems to buy you a little bit more time.