Agreed. It hurts environment reproducibility. It's best when the same binaries flow from environment to environment. That way you know that the binary you built

Agreed. It hurts environment reproducibility. It's best when the same binaries flow from environment to environment. That way you know that the binary you built and was tested by QA in the QA environment (not branch) is the exact same build moving to Production, not some entirely fresh rebuild possibly affected by unintentional merge conflicts or hidden integration problems.