What I meant was that someone taking you out gets to decide how you are no longer part of that conflict. If they choose that you die, you get to throw your death curse as you always own your death scene. If they dictate that you're knocked out, you don't actually get automatically get to say "I launch my death curse instead". The situation might be such that you could, but it's not necessary by either source fiction or rules.
If you chose to death curse (as a concession for instance), then yes, of course your character is killed. (Even though that might not mean the character is completely gone; for a superb example of a mechanic-light, narratively masterful death curse, have a look at the
climax of Haru's PbP Cradle of Darkness! Link is of course very spoilery for the story, I recommend reading it in full instead.)
Most death curses are
not continuous effects, Maggie's is explicitly practically unique in its longevity. Most, even from very old and experienced wizards, are immediate and very violent, since the circumstances of their use usually don't leave terribly much time to consider more complex options and once emotions tend to lean toward direct, retaliatory action.
While the Free Will-aspect is interesting, the only non-mortal suspected of being capable of a death curse is Mavra, and BCV are specifically by WoJ on the very low end of free will.