Errr.
Let me put it like this: it all adds up to normality.
No matter how many times you say "quantum", it doesn't make it a good idea to fill submarines with bombs.
If your reasoning leads you to believe otherwise, you'd better check your reasoning again.
Hint: Let's say I play in a lottery. Do I make the situation better for myself, if construct a device that destroys Earth and kills all possible observers in case I don't win the lottery?
Seeing my point here?
I don't say quantum - so called QI works in the big world which may be non quantum, just large enough to include many copies of the Earth.
Egan law - it is not Egan's, it is not a law and it is not true, and some one who tried to question it was extensively downvoted and leaved LW.
Most submarines are already filled with bombs.
Anyway, I think that big world immortality has small chance to actually work (in predictable way), so it would not be wise to use it as any first line defence. But it may be used it third line defence.
For example, if I build a space ...
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