Fantastic write-up. Thanks for sharing.
Shameless plug: I work on CopilotKit - open-source copilot building blocks for react apps. Designed to alleviate exactly the pain points in the article. Devs define simple Copilot entrypoints--
state (frontend + backend + 3rd party), action, purpose-specific LLM chains, etc. And the CopilotKit engine takes care of the rest.