It's kind of buried in the article, but it's worth noting that this vest is meant only to guard against solar storms, not cosmic rays; those remain a significant problem.

> The vest, though, does nearly nothing against galactic cosmic rays (GCR), which are the other major radiation source astronauts face. Unlike solar storm radiation, GCR arrive continuously at much higher energies, which makes them harder to shield against. “Using the vest against these rays would not be reasonable,” Houri says. “You’d have to wear it at all times.”

See for instance this article on how the cosmic ray problem would affect a Mars mission: https://mceglowski.substack.com/p/radiation-tradeoffs-for-ma...