Waypoint-OPD: Transferring RL-Induced Policy Shifts via Gated On-Policy Distillation

Improves policy-shift distillation by using an intermediate checkpoint of the same RL run as a waypoint: early and late changes in the teacher's relative action preferences are compared and the endpoint shift is gated (suppressed) when they point in opposite directions. Costs only one extra frozen-teacher scoring pass and wins in all six domain-student settings across Qwen3-8B/14B/30B-A3B students on math and code reasoning.