If you think you could write a substantial pull request for a major machine learning library, then major AI safety labs want to interview you today.
I work for Anthropic, an industrial AI research lab focussed on safety. We are bottlenecked on aligned engineering talent. Specifically engineering talent. While we'd always like more ops folk and more researchers, our safety work is limited by a shortage of great engineers.
I've spoken to several other AI safety research organisations who feel the same.
I'm not sure what you mean by "AI safety labs", but Redwood Research, Anthropic, and the OpenAI safety team have all hired self-taught ML engineers. DeepMind has a reputation for being more focused on credentials. Other AI labs don't do as much research that's clearly focused on AI takeover risk.