Best Coding Harness for Qwen3.6 35B?

I've been happily using GitHub Copilot for 7-8 months, primarily in Visual Studio and VS Code, mostly with the built-in flagship models and have felt like the output is worth the cost. Lately I've been playing with a lot of different local LLM models and decided to try using Qwen3.6 35B on some non trivial programming tasks within a repository that is 10ish years old with thousands of files and multiple languages in it. I've actually been really impressed when I use the "ask" functionality as it's been able to find and suggest correct fixes. When I've used the "agent" functionality I've found it often gets stuck in a loop and doesn't apply the changes or auto update the code. Seems a miss match between GitHub Copilot and this specific model.

I get that it's a model not tested with Copilot and am wondering if there are code editors people are using and happy with that are specifically designed for smaller local LLMs.