Do you understand my solution?
I confess that I don't.
I can see using 45 voltage dividers but I don't get the banks, as each "bank" has to have the same 0v reference what is the difference between that and just a MUX?
I do admit that say a 45:8 (or whatever) MUX would be much cheaper, but I think you'd probably want to customise each voltage divider to get full resolution.
Rob