Analysis following topic base on materials available from internet in recent two or three months: It seemed that multiple model service providers are implementing smart/intelligence-level-based model routing in their backend now a days. There's already some level of similar feature embedded in coding clis like claude-code, gemini-cli, opencode, etc. What is the best place to implement model routing from your opinion? What is the best way to implement it considering about user friendliness, trusting, user-s-cost, user-experience, performance and accuracy.