The absolute most important protection for 50A is an open neutral which will cause very high and low voltage on the 2 power legs. Next is low voltage on either leg especially when connected to a 20A or 30A pedestal. This device offers no automatic disconnect for these conditions and others say at 2AM. OK if you plug it in and are watching the display it "monitors" some conditions. The "surge" device which your are asking about and a Energy Management System (EMS) which protects and disconnects shore power when a fault occurs are very different devices. Of course a EMS costs more.
My PI HW50C detects 10 faults and disconnects utility power. The display and fault codes are visible inside the RV.