"clearly" you are not understanding what those charts say. NEC ratings for current versus wire size are only for intermittent non-continuous loads. NEC is very clear that it is forbidden to run 30A continuous on 10 gauge wire. This is a specific difference between the electrical codes in the U.S. versus the code standards in Europe. In European code, they actually do specify the wire gauge ratings based on continuous 100% rated current usage for a circuit rating. But that is not so in the U.S. NEC.10ga is clearly suitable for carrying 30 amperes according to NEC ampacity charts
This.The 30A rating is for "non-continuous" 30A, as the heat may/will accumulate at the 30A level, but not at the 24A.