Samurai's Strength before Death 0 HP only?

From what I read, this feature *only* triggers when you hit *exactly 0 HP* (RAW). I've not played with years of experience, but when I have played, getting to *exactly 0 HP* seems to be rather rare. I've read some say that they get close to 0, then do something to suffer the last bit of HP (falling?), to then trigger it. Otherwise, it doesn't seem like it triggers that often.

So, I was wondering if, as an alt (RAI?), instead of *exactly 0 HP,* if some do "0 or a little under?" If so, how do you handle that?