RE: IMax b6 noob help
I don't think that charger is set up for that, ohio. I'm sure it's do-able, but it's not advisable. As you wondered, balancing becomes an issue. Not knowing the charger's firmware, I don't know how it would handle two packs connected with a y-harness. Especially if only one, or none, of the balance taps are plugged into the balance port. I don't think my charger would allow it.
Why risk it? If you need to charge two packs at once, buy a charger capable of doing so, eh?