I use a 50A portable Progressive EMS when on the road but haven't used it at home. Hadn't thought of it. Good idea. Only use 120V to keep batteries charged, all else is off.
BTW I purchased EMS in 2008. Plugged in to 30 foot, 30A TT 24/7 for 8 years. Worked great. This summer traveling in MH severe rain on east coast found it's way into the EMS through the outlet I believe and it stopped working. The older ones didn't have the plastic cover over the outlet. Replacement within a week under warranty and Progressive even paid the shipping. Can't say enough good about Progressive.
03 Workhorse 22K Winnebago Adventurer 35U
Honda 2012 CRV and 2001 Dodge Dakota Quad