First impression for just the minimal-versions aspect, I feel like CARGO_BUILD_RESOLVER_PRECEDENCE=minimum cargo generate-lockfile / cargo generate-lockfile --config=build.resolver.precedence='"minimum"' is more confusing than cargo generate-lockfile --minimal-versions or similar. This is a transient step that I take in a single CI job or on rare occasions locally to debug issues, not something that I want configured long-term like the rest of the config file is normally treated as.
In general I am similarly wary of .cargo/config.toml in repos as I am of rust-toolchain.toml. Removing those from packages to avoid unintended influence is another step that docs.rs has to take to try and get a clean build. I have run into multiple occasions where there have been problems with their interaction with my global config, like We need configurably additive rustflags!.