Haven’t used an Imax in years. I found them to be cheap, unreliable, and short lived.
If using the storage function the charger is designed to discharge the battery to around 3.7V per cell. For the Tornado it leaves the battery around 22.8V. Don’t use the discharge function unless you set the discharge rate and watch voltage levels very closely to terminate the cycle at the appropriate time.
As for discharge rate, use a 1C setting for the battery size. That establishes a 1 hour (roughly) cycle period.