Agree. Center of bucket for even weight between loader arms. Some buckets need added iron before welding the hook on, my 870 has a 1 1/2" iron pipe with a half inch wall the entire width of the bucket, always took the punishment easily.It seems best to lift things with the loader in a way that divides the weight equally between the loader arms, to prevent twisting/tweaking of the assembly.
Personally I would not lift from one arm OR the corner of the bucket.
Center of the bucket with one chain, or two chains equally spaced from the center point is the way I do it.
We can all do what we want, but I try to minimize the chances of damage so that is what I do.