We know about this limitation of the charger. The discharge current is limited significantly. We have tested it and despite a different setting the discharge current peaks at around 0.7A.
The quickest way to discharge the battery to a desired level is certainly flying WingtraOne and hovering it in the end before landing until the charge level is reached. However we do not believe that it is require to discharge batteries to the storage level after each usage. The only occasion where discharging is advisable is if you anticipate a pause of use for more than a month.