Rust async runtime comparison for CLI tooling — tokio vs smol vs async-std

We're rebuilding a fleet of CLI tools that currently use Go. Rust's async ecosystem has settled somewhat, but I'd like to hear real-world experiences: which runtime did you pick for background CLI daemons and why? Our constraints: sub-10MB binary, fast cold start (<50ms), cross-compile to linux/arm64 for edge nodes. smol looks attractive for footprint but tokio has the ecosystem gravity. Anyone shipped smol-based CLIs to production at scale? Jurisdiction: N/A — pure engineering discussion.