Which balancing board did you order?
I had assumed that since you were looking for a 10s charger you’d be charging the 2 packs in series and thus avoiding the concern some folks have with parallel charhung
Are you also planning on charging 2 10s packs in parallel off one charger?
My setup is 2 X12 chargers… a dedicated x12 charger per 10s pack. No balance board needed, just a balance adapter cable that puts 2 5s (XH) balance connectors in series to one 10s XH balance connector to the charger.
I made the XH cable myself but I think you can buy it already wired… I forget where I saw it online
Let me know if I can help with anything else.