I'd really like to understand why they didn't just also have a small container for this running. The only reasoning given in the article is "another container to run and manage" which Docker compose, TestContainers, etc will make trivial.
If a dev came to me and suggested we go this route I would need to seriously be convinced. They even explicitly call out this is only for local development meaning it's not like this was piggy-backing off of a secondary need for a Rust redis anyways. Insanity.