I couldn’t find any initiatives to package this into Fedora, which surprised me, as nix is an amazing technology, helpful specially on workstations (ahem).
Is there a way to install it with the usual ergonomics of an rpm? Is there any initiative to package it into Fedora?
In your case, you wouldn’t want to push nix into an overlay. Isn’t it actually far better for it not to be a package on Silverblue?
It has been a while since I ran nix outside of nixos but aren’t the nix commands updated by nix itself? You should already be using nix to update all the software you install with nix.