Could you please explain the thought process that led you to settle on Fedora? Thanks!
Universal blue, the starting point for this project, is fedora based. https://universal-blue.org/ No other distro has the same level of immutable tooling or support for immutable variants at this time. Also, Fedora has selinux tooling and enforcing mode out of the box and they're working on further selinux improvements upstream, so we'll get that for free.
opensuse..tumbleweed..transactional server