Hi,
If low voltage is the worry, then an autoformer may be a better investment than the surge units. No one makes a surge device that cuts out at 108 volts, which is my personal comfort level.
Personally, I get around low voltage by doing "double conversion" where I plug in just the converter to shore power and then run the rest of the RV from the inverter. I caused two auxiliary shore power cords to be added to the OEM 30 amp. One operates two plugs and the converter, the other one plug plus the water heater. I used male and female plugs, so I can switch back to the OEM configuration in under a minute.