I have the Hughs Autoformer https://hughesautoformers.com/produc...ter-and-surge/
and the Hughs Power Watchdog https://hughesautoformers.com/produc...ter-and-surge/
Both seem to work fine. I am only aware of a couple instances where the Autoformer boosted the voltage, but you usually don't know. No issues yet that the Power Watch Dog had to resolve except the time I did not get both AC legs connected at the same time; as advertised, it shut everything down. I like the Bluetooth feature on the Power Watch Dog.
Mine are installed permanently, but portable is an option. I use the ones with plugs (vs hardwired) for ease of configuration. If I had to take either device off-line for any reason, it would just be a matter of unplugging it.
The yellow adapter is the output of my inverter. When dry camping, I pull the plug from the PWD feeding the transfer switch and plug it into the yellow adapter. That way my inverter powers the entire 5th wheel. Of course, I turn off the breakers for AC, microwave, refer, converter, etc.