A setting changed through mesh-controller.settings rewrote dunstrc, but the running dunst kept the old font and width until the next login. Declare the package's dunst.service in the account's manager, without a state, with reload-on the configuration, so the node-engine runs its ExecReload (dunstctl reload) and what is on screen stays. Add dunst_reload to do the same on demand and say the font and width the files set.