You'd better take harness and provider as different parts. In your case, I think the major issue is OpenCode go provier, not necessariy OpenCode harness.
If you just want to have an alternative provider, I would recommend OpenRouter, which has provider fallback and model fallback. You can try OpenCode + OpenRouter instead of OpenCode + OpenCode Go; Or you can also try different harness such as Crush and Pi, in this way you have a setup like OpenCode/Crush/Pi + OpenRouter.
If you want to have a even better harness experience, then I would say the native harness from codex or claude code is still the best, you don't have give away the native harness just because it binds to the original models; with cc-switch you can use the native harness with alternative models like DeepSeek, cc-swith does lots of work to support this setup in best effort.
For example, the latest Codex uses Responses API, while lots of cheap models are still using Chat Completions, then with cc-swith, you can have:
Codex Responses API
↓
CC Switch local router
↓
DeepSeek Chat Completions
With this setup you have Codex native harness, and DeepSeek model as the underlying model.
Or even better, you can have:
Codex/Claude Code
↓
CC Switch
↓
DeepSeek + OpenRouter/Z.AI/MiniMax fallback
Then you enjoy the best harness and any model that suits into your workflow.
I had a pleasant experience with Pi and also I saw some charts where Claude and Codex had better performance with Cursor than their own native harnesses
You'd better take harness and provider as different parts. In your case, I think the major issue is OpenCode go provier, not necessariy OpenCode harness.
If you just want to have an alternative provider, I would recommend OpenRouter, which has provider fallback and model fallback. You can try OpenCode + OpenRouter instead of OpenCode + OpenCode Go; Or you can also try different harness such as Crush and Pi, in this way you have a setup like OpenCode/Crush/Pi + OpenRouter.
If you want to have a even better harness experience, then I would say the native harness from codex or claude code is still the best, you don't have give away the native harness just because it binds to the original models; with cc-switch you can use the native harness with alternative models like DeepSeek, cc-swith does lots of work to support this setup in best effort.
For example, the latest Codex uses Responses API, while lots of cheap models are still using Chat Completions, then with cc-swith, you can have:
Codex Responses API ↓ CC Switch local router ↓ DeepSeek Chat Completions
With this setup you have Codex native harness, and DeepSeek model as the underlying model.
Or even better, you can have:
Codex/Claude Code ↓ CC Switch ↓ DeepSeek + OpenRouter/Z.AI/MiniMax fallback
Then you enjoy the best harness and any model that suits into your workflow.
I had a pleasant experience with Pi and also I saw some charts where Claude and Codex had better performance with Cursor than their own native harnesses
Moshcode cli