The guillotine?! Which your brain/consciousness can stay functioning for 30 sec and up to like 4 min? That is better than nitrogen asphyxiation?
Now by all means by your criteria, yes it is fast and there is very little room for failure. However I think we still don’t know if it is as painless as we perceive it to be with how long you can stay concieous.
Regardless I am also of the same mind that we could move away from capital punishment as a society.
Do you want real life Exo Squad? Because this is how you get Exo Squad.
Joking aside, while this may be faster, I think it would safer in the long run to keep focusing on actually getting to space and achieving faster than rockwt/thruster propulsion and let evolution work with that.