[boekel]

Please be informed that the ir measurements from the CellPro are not much usefull for 'big' batteries.

I think this is because of relatively low C-rate and the thin wiring.

 

[boekel]

What "work" are you having the cellpro do before you start charging?

I thought they were only useful for passively monitoring voltages?

I think you're thinking about the CellLog 8 (monitor)
https://www.progressiverc.com/celllog-8s.html

the CellPro chargers can do charging / discharging / monitoring:
http://www.revolectrix.com/pl8_description_tab.htm

Anyway, lots of writing while the simple thing I would do is:
Charge till first cell reaches maximum. Than top up other cells with separate charger (like the CellPro).
Than discharge (by driving) until first cell reaches minimum. bridge that cell, etc. until you're left with the cells that are good enough to give you the desired range.

And yes, please use a bms, even if it's just a monitoring only system, you would have saved those cells with it...