tl;dr, we need more time examples and research to say anything authoritative, but anecdotally things look very positive. One excerpt,

There have been no known major injuries of any community responder on the job so far, according to experts. And data suggests unarmed responders rarely need to call in police. In Eugene, Oregon, which has operated the Crisis Assistance Helping Out On The Streets (known locally as CAHOOTS) response team since 1989, roughly 1% of their calls end up requiring police backup, according to the organization. Albuquerque responders have asked for police in 1% of calls, as of January. In Denver, the Support Team Assisted Response (STAR) team had never called for police backup due to a safety issue as of July 2022, the most recent data available. In Durham, members of the Holistic Empathetic Assistance Response Team (HEART) reported feeling safe on 99% of calls.

Many communities are still sending alternative responders to a narrow subset of calls, and debating whether it’s safe to expand their scope. For example, many cities will only send community responders to situations that are outdoors or in public spaces. Programs are also divided on whether disputes between neighbors or within families are a proper place for crisis responders, or calls involving suicidal threats.

Archived at https://web.archive.org/web/20240725114047/https://www.themarshallproject.org/2024/07/25/police-mental-health-alternative-911