Costco usually vets their products pretty thoroughly before they buy. I've talked to HQ and the staff are not dummies. They impressed the heck out of me.
The inverter looks just like my 1000W Xantrex prowatt. The charge controller won't handle three modules in series but reading between the lines in the manual, it may be MPPT flavor.
Regards, Don My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.