It's been three months, but I finally have a working battery management system. Here I'm testing it with 24 cells in series and the Manzanita charger. I deliberately discharged one of the cells, and the system is bringing it back in balance as it charges the whole pack. It's been a lot of work, but this system should give the best life possible to my pack.
I'm sure there will be some fiddling with the control algorithms, but at least the hardware is done.