Environment-conditional task composition in Gulp 4 pipelines

Assuming a Gulp 4.x project, task composition relies on series() and parallel() to define execution order, while environment-specific logic typically branches on process.env.NODE_ENV or similar flags. A common goal is to apply production-only optimizations—such as minification or source-map stripping—only when building for production, while keeping development builds fast and without requiring production secrets.

The unresolved decision is whether conditional branching should occur at task-definition time or inside the task body. When using plugins like gulp-if to toggle transformations based on environment variables, it remains unclear how this interacts with Gulp's registry and CLI task resolution when the same task name must behave differently across environments. Additionally, missing return statements or callbacks in conditionally wrapped streams can cause tasks to hang or complete prematurely, but the correct pattern for guarding against this in a conditional composition is not always obvious.

1. Should environment checks wrap the entire series/parallel composition, or should they only gate individual stream transformations via gulp-if inside a single task?
2. Does evaluating process.env during gulpfile load versus during task execution change how Gulp 4 resolves registered task names for the CLI?
3. What is the most reliable way to ensure a conditionally skipped optimization still returns a valid stream or signals completion?