Bug: Haiku 4.5 blocks advisor despite blog claiming Haiku+Opus advisor support

Summary

The Claude Code UI states "The current main model (Haiku 4.5) does not support the advisor" when switching to Haiku. However, the official blog post The Advisor Strategy explicitly documents Haiku as a supported executor with Opus as advisor, with benchmark results showing significant performance gains.

Steps to reproduce

1. Run /model → select Haiku 4.5
2. Run /advisor → shows "The current main model (Haiku 4.5) does not support the advisor"

Expected behavior

Haiku should support pairing with an Opus advisor, as documented in the blog:

"The advisor strategy also works with Haiku as the executor. On BrowseComp, Haiku with an Opus advisor scored 41.2%, more than double its solo score of 19.7%."

The blog also shows cost-efficiency data:

• Haiku solo: 19.7% score, $0.20 cost
• Haiku + Opus advisor: 41.2% score, $1.07 cost
• Trails Sonnet solo by only 29% in score but costs 85% less per task

Why this matters

Haiku + Opus advisor is positioned as "a strong option for high-volume tasks that require a balance of intelligence and cost." Blocking this pairing in the product contradicts the published strategy and removes a cost-effective option for users.

Environment

• Claude Code v2.1.100
• macOS (darwin)

References

• Blog: https://claude.com/blog/the-advisor-strategy
• Benchmark table: Haiku 4.6 executor + Opus 4.6 advisor performance data