Yea, I thought hobbycity did too, but I can only find the adapters to turn 2x 3s packs into a 6s, or split a 6s pack into 2 x 3s :(

My BC8 can do 7 cells, but its only 150W charge, so it'd be slow anyway.

That new 7s hyperion charger looks the goods, but same problem, how to connect up the balance taps on the 4s and 3s? :(