If you have copied bank 1 to bank 2 both will now be normal mode. You can confirm this in the software. Set one bank for 25% gain and the other for 40% gain. Use the 25% setting for your first flight. Once you are comfortable you can try the higher gain setting. Every airplane is different but these settings should be a good starting point. Higher gain settings are useful for slow flight such as takeoff or landing. Most guys start by assigning the gain/mode control to a 3 position switch. Your DX-18 has a fairly good gyro control function that will allow you to set gyro gain by flight mode. Create 3 flight modes for takeoff, landing, and cruise. You can then set the gyro gain for each. This way you don't have to remember to switch a separate gain switch.