Agreed on the asymmetry. That's why close calls go up a tier: overspending costs money, but a confidently wrong debug costs much more.

To answer your question: no, not yet. Right now I only know which tier a prompt was sent to, not whether a cheaper model would have handled it. So I can't yet say how much the router saves.

My plan is to log every routing decision (prompt hash, scores, tier, escalated or not) to a JSONL file. Then I'll take a sample of prompts that went to Opus, re-run them on Haiku and Sonnet, and compare the answers. That shows how often Opus was overkill, and turns "it probably saves money" into an actual number.