Thanks for the feedback @madmaxbr5! We are soon going to have a large upgrade that fixes this, and have also supported easily integrating custom proposers (https://gepa-ai.github.io/gepa/guides/claude-cli-as-proposer/) for a long time now.
The stock proposer is built in a way that it can work with the smallest models (initially GEPA was launched with tests on Qwen3-8B, and maintains backward compatibility so far), so we have avoided including detailed instructions there.
Dropbox discussed how they include some very lightweight instructions in the feedback returned to GEPA that prevented overfitting, and instead got good generalization (https://dropbox.tech/machine-learning/optimizing-dropbox-dash-relevance-judge-with-dspy).