For 12 years I used a Prosine 2.0 and plugged into 30, or 50 or not plugged in I left the inverter side "Turned on" full time.. This is a inverter/charger (I turned the charger off cause I like the Progressive Dynamics 9180 with wizard better) but left the Inverter side on, With Shore power it went into Standby mode automatically..
When Shore power failed, and it has many times.. Televisons, computer, Microwave, et-al did not even blink, only thing that Blinked was my Moto-sat In-motion Sat dish.. And I don't use it anymore.