Where did you see that they used NAS? Their preliminary results show it works even for the baseline model
they did a lot of manual hyperparameter optimization, and spend a fair amount of time unpacking the rationale for their choices, including a negative results section (!) in the appendix
they did a lot of manual hyperparameter optimization, and spend a fair amount of time unpacking the rationale for their choices, including a negative results section (!) in the appendix