Choosing Between Alert Popups and Message Logging for Quiet Wolfram Kernel Workflows

The goal is to signal important conditions in Wolfram Language code without creating notification noise that disrupts automated, headless, or remote kernel sessions.

Using Alert[expr] produces a modal dialog that demands user acknowledgment and can generate system notifications, but it halts kernel processing until dismissed and may fail silently in Engine kernels lacking a FrontEnd. Conversely, Message[expr] routes text to the Messages window where it can be suppressed, filtered, or redirected via Off, Quiet, or $MessageList, allowing quieter background evaluation without interrupting control flow.

The unresolved decision is which mechanism provides reliable visibility in interactive FrontEnd contexts while remaining truly silent in headless or remote deployments, especially considering version‑specific changes to Alert behavior in Wolfram Engine.

Which approach ensures a visible cue in a FrontEnd session yet stays silent in a headless Kernel?
How can one scope suppression of Message to avoid muting unrelated warnings elsewhere in the same session?
Under what Wolfram Engine versions does Alert silently return $Failed or produce no output, and how does this affect noise‑constrained workflows?