Review for NeurIPS paper: Safe Reinforcement Learning via Curriculum Induction

Weaknesses: There were two primary weaknesses that I noticed in the paper: (1) The paper notes that the framework is different from prior curriculum learning work due to learning from prior learners, allowing it to be "data-driven rather than heuristic," but the consequences of that aren't explored. In particular, this may mean that many agents must be trained prior to getting to a good curricular policy, and this may be problematic for practitioners. This fact is somewhat hidden in the experimental evaluations because the evaluation of the optimized sequence of interventions doesn't include the performance of the first 30-100 learners. It would be helpful to either include a clearer argument for the importance of learning the curriculum policy over other approaches or to discuss the possible limitations of needing to learn from many learners (and perhaps the robustness claims would mitigate this limitation to some extent). I would also have liked to see results (perhaps in the appendix) for the sensitivity of the results to the number of learners prior to reaching an "optimized" point.