Run both Once and Kamal on the same machine

[korneel]

I would like to use Once for hosting public Docker images, and Kamal for hosting private apps. I run Kamal proxy on a different port than port 80, so I can run a Caddy proxy in front of it on port 80 to handle SSL, because my machine is not publicly accessible (it's only accessible in my Tailscale network). Once proxy seems to require running on port 80. Can I run it on a different port? Or can Kamal and Once both use the same single proxy?

Or maybe it's better to not use Once for my use case and host the public apps as Kamal accessories instead?