Any soul is the property of its creator
The whole electric computing mass know as the brain is probably millennia away from ‘downloading’. If ever.
“We can never know the composition of the stars.”
“Everything that can be invented has been invented.”
“No one needs more than a megabyte of memory.”
I agree with your premise about ever being able to do this, but the human brain is only partially an electric computing mass.
It is also a chemically wet processing unit. While electric signals are sent from neuron to neuron, neurons use chemicals in the brain to allow/disallow reception of synaptic gaps... That's why melatonin can make one sleep or be an insomniac, for example.
Without this, any weak electrical signals, static electricity, for example, would make you convulse or have a "brain storm".
The chemical-electric brain is what we use. Replication of this intricacy will take a long time, if ever.
Even if you did you simply wind up with an AI of your consciousness running, you will still very much be dead