Really dumb extension cord Q

While the other posters are correct about the ratings of the cord and connectors (at least the official and guaranteed ratings), it's worth noting that the circuit breaker protecting the circuit will still be a 30A breaker and so you run the risk of overloading the connectors without it tripping. It would be wise to keep tabs on the electrical usage to prevent an overload.

As a practical matter, if the connectors are not getting at all warm, you're being safe regardless of their putative ratings...but you will not find me posting any suggestion to exceed the official ratings here.