Pretty easy to add L2 to the circuit board. But then again standard MOVs last 1-2 years down here. It's tough to predict as I have seen filled USA RV parks with running A/C's turn the local grid into a veritable electron house of horrors. The idea of adding an inductor is intriguing but one designed for a mere 30-amperes is daunting financial wise. And it won't fit.
I look at my Sola UT system and shrink. It isn't all that great of capacity, yet it cost a fortune. Maybe ridiculously more expensive in 2015 I do not know. Laugh on but a field of solar panels and a low THD sine wave inverter starts to sound feasible.
Filled RV parks are murder incorporated as far as damaging electrical conditions are concerned. A dedicated service drop transformer is usually clean as is an inverter generator barring the inductive spikes and line phase shift caused by high head A/C restarts.
