The author of the VS Code extension Double says that he was motivated by two years of observing how the GitHub Copilot team did not fix user interface flaws:

• incorrect closing of brackets,
• poor comment autocompletion,
• lack of auto-import of libraries,
• incomplete operation of the multi-cursor mode,
  and all other problems of the outdated GPT-3.5 model (because GPT-4 is used where the system decides).

The latest version of Double integrates the Claude 3 Opus model from Anthropic, which, according to some benchmarks, surpasses GPT-4. In addition to Opus, GPT-4 Turbo is also present. Double.bot was accepted into the Y Combinator accelerator. 50 requests to any of these models per month are available for free. A full subscription costs $20 (and GitHub Copilot now costs $10 without slash commands, $19 with them).

The extension is not on open-vsx.org.
To register, you need to enter the code from the SMS - it never came to my Ukrainian number.