I've looked into this too, but it always felt like it's best suited for a "one app per server" model, and not really like Dokku which makes it easy to run many workloads on a single server.

Did I misunderstand something there?

I’m pretty sure multiple apps is on their public roadmap, I’m sure I read it somewhere.

Recently DHH posted on twitter that Kama v2 will have support for multiple apps on a server.

I've never tried the many-apps-per-server use case and I don't think it's supported. We use it in production where its more common to have many-servers-per-app.

I’ve got two apps running on two servers (ie both on both) using Kamal and Traefik and it works great. I didn’t set it up but I deploy with it almost every day.

I already run multiple apps on a single server with Kamal and it works fairly good. Sometimes there are some issues especially if you use similar resources across system such as redis. But overall it is stable and works good.