I don't really buy the idea pulling out the engine would have to kill her. I mean, we know for a fact it has to be possible to pull out what's in someone's chest and replace it with an infernal engine of some sort without killing them- if it wasn't, we couldn't possibly have Karlach alive with an engine in her chest instead of a heart. Frig, she just straight up shoves upgrades for it into her chest without serious trouble on two different occasions
