

Nix in single user mode can apparently work with SELinux in enforcing mode, although AFAIK binaries installed via Nix can not have SELinux metadata which could be an issue for some programs.
Determinate Nix claims to have seamless integration with SELinux (unlike upstream Nix and Lix, but it’s not a fork, alright whatever you say Eelco). Using that and removing the proprietary garbage their installer also adds might be easier than making regular Nix play nice with it.

You can run the LXQt Wayland Session with Hyprland as compositor. You can also forget about the session and just run the panel in a startup command or a systemd service, although I’m not sure if all widgets will work correctly this way.
XFCE also has experimental Wayland support; Hyprland isn’t officially supported but IIRC it uses the same wlroots protocols as the supported Labwc so it should work. Documentation is fairly sparse even compared to LXQt though and it’s a bit buggy, I personally haven’t gotten it to work (but others have so it’s definitely possible).
Edit: Also, Waybar has task bar widgets too. But it doesn’t support any kinds of “popup” like start menus or control centers, you just have the bar.