When the transmit power is set to Auto, EnGenius APs are broadcasting at maximum transmit power. Not all deployment should have AP broadcasts at maximum power.
Max power is not recommended to ensure that weak client devices (e.g. smartphones, tablets) will be able to communicate back to access point. For dual band APs, power level should be at least 4 dB higher on 5GHz band as compared to 2.4 GHz band. Below is the recommend power decibel settings: