[HarHarVeryFunny]

I wonder how much this harms performance when using Claude Code with non-Anthropic models?

It would be interesting to see benchmarks, including these changes, of how harness affects model performance - including both model-agnostic harnesses such as OpenCode and Pi as well as increasingly model-specific ones like Claude Code and Codex.

For the model-agnostic/model-inclusive harnesses like OpenCode it would make sense (if they don't already do it) to keep the harness itself generic and then have per-model sets of skills designed to get the best performance out of each specific model.