I work in the embedded space. I'd absolutely love to have a tool to build immutable, signed distro images which I can push to devices with a/b style updates. I imagine you can do this with mkosi, but it doesn't quite feel like the intended use case.

Most immutable distros (this included) are developed with the idea that you'd run local commands on the machine, and update a single OS image in place. That gets pretty unwieldy to manage across a fleet of devices.

Right now the industry standard tooling for building truly immutable images for embedded devices is Yocto. It works well, but it's incredibly complicated and has ridiculous build times because it insists on building every single package from source. It's utter madness that building a Linux image for a common ARM64 processor requires me to compile the Rust compiler myself.