In some research I did before, 52% of all hangings were complete suspension with feet lifted above the ground; so I'd assume they stepped off of something, and the remaining 48% was some form of partial suspension were the body was touching the ground. most cases, an instant death in hanging requires a drop of at least 6ft to break the neck. In cases of short drops and suspension where the body is touching the ground you'll either fall unconscious and die from compression of the carotid arteries which bring about unconscious within a matter of seconds to up to approx 20 seconds. If you don't manage to compress the carotid arteries and instead your trachea is crushed preventing you from breathing, I've seen that you could be 'fighting the noose' for up to 2 minutes. How accurate that is? I don't know because it's not my research, I just found the information online from doctorates and PHDs.
If your going for a short drop or complete suspension, I would suggest finding 'your sweet spot' first as compression of the carotids will make the process quicker and leading to hypoxia rather than crushing your trachea which leads to asphyxiation.
I'm considering hanging also if I can't go ahead from carbon monoxide