The full-stage+kv dump (1.7GB/file, synchronous in-forward) hung/crashed a scheduler child. Trim to the residual-stream trajectory (attn_in/attn_out per layer) + q_all + final_hidden (~tens of MB/forward) — enough to localize the first divergent layer (Stage 1). Drop dense-space kv_cache/topk (not comparable anyway) and the MoE substages. Dumps go to local NVMe (/ssd) to avoid beegfs stall. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>