The "balancer plug" simply brings out the terminals of the individual cells in the pack... this allows you to charge each cell individually, guaranteeing that you never exceed the max voltage for that cell. To do a balanced charge with a single channel charger (i.e. a charger that can only charge one battery/pack at a time), you'd have to make some connectors that would bring out each cell to the charger, and charge them one at a time... one after the other. A quick way to do this would be to charge the whole pack in series (using the discharge connector) to about 80% capacity, and then use the balancer plug to top off each cell individually.

From what I understand, the charger that comes with the CX is a balanced charger, which actually charges each cell individually and does them all simultaneously using the balancer plug.

If you are careful not to over discharge or over charge your packs, you probably won't have a problem with the balance of your pack. I'd recommend just charging the pack with the "discharge" connector, and perhaps use a voltmeter to check the voltage balance on the individual cells occasionally... and then rebalance them if they get too far off.