bgnotify global threshold limits per-command control in Oh My Zsh

Goal is to use Oh My Zsh bgnotify plugin to receive desktop notifications for long-running foreground commands while keeping alert noise low.

bgnotify emits a notification when a command exceeds a time threshold and the terminal is unfocused. Noise reduction relies on the global bgnotify_threshold variable and the unfocused-window check. Backends differ by platform and availability. There is no documented per-command allowlist or denylist in the plugin.

This leaves an unresolved design choice between a single global threshold that is simple but may still notify for interactive sessions, and more precise control that would require custom hooks outside bgnotify.

What is the supported way to suppress notifications for specific commands without changing the global threshold? Does bgnotify expose any documented variable or hook for command filtering? How does backend availability affect the unfocused-window behavior on different platforms?