ACE MLPs were also obtained for other Diels-Alder reactions and consistently achieved chemical accuracy (± 1 kcal mol -1 ). This enabled us to perform RPMD in order to introduce nuclear quantum effects, as well as to obtain free energies employing umbrella sampling. While product distributions were strongly dependent on the DFT reference method, they were less dependent on the type of dynamics propagated (classical vs quantum). When computing free energies, MLP-US predicts barrier free energies within the static methods' ranges, which vary by ≈ 3kcal mol -1 . For reaction free energies, larger errors bars were obtained at low temperature due to insufficient sampling. Comparison to experimental values demonstrates that MLP-US provide quantitative accuracy.