Upstream has no such flag, no such module, and no in-flight accounting anywhere in its ingest path. Ours blocked in acquire() when exhausted, which was half of what deadlocked experiment 4, and then sat pinned at its cap for all of experiment 5 while the machine was 86% idle. It arrived in 94e50a0 "make full-network backfill production-ready" with an empty commit body -- no reason recorded, then or since. Worker count is the concurrency bound now, as it is upstream. Removes byte_budget.zig, --backfill-max-inflight-bytes, and the two gauges that would otherwise report 0 forever. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>