As far as the method shown in the link of electro treating the meat this is decades old and our experience was it was rubbish at the time. We had more complaints about the quality of the meat than ever. It could never replace the 21 day plus hanging in the chiller.
I am no expert but FreeForester has the answers on this, hanging a whole carcass is better that hanging the primals, it needs air to circulate freely around or it starts to turn.
I would not worry about hanging over night, keep the fly's off, cut it up and stick to hanging during the winter months.