If you plan to distribute your configuration to a lot of users, you should keep a couple things in mind:
Quickshell will have API breaks in future versions. You should have a way to track specific revisions with your distribution to avoid breakage if a user updates quickshell before you can update your configuration.
With Nix this should be as simple as tracking a specific revision. For Arch, and other distributions without a mechanism to do this, you may want to include a package that builds a specific Quickshell revision with your configuration.
Quickshell can load configurations from a number of different paths. The ideal path depends on how you distribute your config.
If you distribute your config as a set of dotfiles, you should place
the config in $XDG_CONFIG_HOME/quickshell/<name> (usually ~/.config/quickshell/<name>).
Named configurations can be used in the quickshell command by specifying --config or -c
(qs -c <name>).
You should not use the bare $XDG_CONFIG_HOME/quickshell directory as that will
make it harder for users to have any other configuration.
Some configurations are distributed as distro packages. These packages should use a
path in $XDG_CONFIG_DIRS, usually /etc/xdg for their files.
As with dotfiles, named configurations should be used ($CONFIG_DIR/quickshell/<name>).