Me too. I aint got a flex charger, mine is the Apex Sigma Plus. Hmmm. There's a method without using those chargers / dischargers with graphical interface. One can simply monitor the voltage during discharge, and then take samples for a fixed interval. That is, for each 100 mAH measure the voltage. Or for each 20 seconds. Write them down. Afterwards, it's possible to draw the discharge graph. It's a little time consuming, but it can be done.
Preferable, it should be done for several charges / discharges at each method, to ensure the reliability. For example like 5 runs for each charge method. The time schedule should be the same for each test. for example charge, 15 minutes pause, discharge, 24 hours pause, next phase...