bindist USE flag binary distribution source constraint

The bindist USE flag controls whether Gentoo retrieves prebuilt binaries for a package instead of compiling from source. Enabling this flag system-wide can reduce compilation time and bandwidth but may limit access to source code, affecting compliance, debugging, or future modifications. The precise goal is to establish a consistent policy for when bindist takes precedence over source availability across the package dependency graph. Are there scenarios where enabling bindist triggers masked-package errors without clear attribution? What policy mechanisms can balance binary convenience with source accessibility? Does the bindist flag propagate uniformly through reverse dependencies?