PSA regarding safety with the NEMA 14-30 adapter:
If you order one, make sure it is able to probably "click" and lock into your connector. I ordered one from the website and due to a manufacturing defect that caused a piece of plastic to protrude from the locking stub on the adapter, it was not able to lock into the cable connector. I was able to easily pull the adapter off the connector even without pushing the button.
This could pose a safety hazard if you are trying to unplug the entire thing from the wall socket and only the cable comes out but adapter stays in the outlet.
I went to Fremont service to exchange it, and guess what, they found more adapters in their stock with the same issue. They finally found a good one, and said will follow up with manufacturing to see what's going on with the defect.
So anyway, if you buy one, make sure it locks!