It does not matter in the sense of distro hopping because most people are hopping without a goal, or if they have a goal the goal is possible with the current solution too.

But in this case its different. You have a goal and security has its requirements. If you want to protect against supply chain attacks, using Arch Linux would be a risk for example.

It always depends. Your goal is security and you found out about secureblue. Alone with that you are far ahead of elses people who only hop distros for no reason.

You can try secureblue and if it does not fit your use cases try Fedora and tinker a bit with bubblejail and other hardening yourself, with that you will learn a lot which is even more valuable than just using a secure os. As far as I know Fedora uses SELinux already which is pretty good.