In https://github.com/phetsims/curve-fitting/issues/71, I see a discussion between 2 developers about completing model.md and implementation-notes.md. But I can find no paper trial indicating that the lead design (@amanda-phet) reviewed and signed off on model.md. It's typically reviewed by the lead design because the audience for model.md is non-developers, including teachers. This is also typically done before code review, since model.md is one of the first things read by the code reviewer.
Related to code review https://github.com/phetsims/curve-fitting/issues/143.
In https://github.com/phetsims/curve-fitting/issues/71, I see a discussion between 2 developers about completing model.md and implementation-notes.md. But I can find no paper trial indicating that the lead design (@amanda-phet) reviewed and signed off on model.md. It's typically reviewed by the lead design because the audience for model.md is non-developers, including teachers. This is also typically done before code review, since model.md is one of the first things read by the code reviewer.
See for example https://github.com/phetsims/gas-properties/issues/79, the review and sign-off of model.md for gas-properties.