One header, side tab and chat for every Wicko Waypoint site. One script, one config file per site, sealed off from each site's own styles.
<script src="https://kit.wickowaypoint.com/v1/wicko.js" data-site="packard" defer></script>
Everything else (links, colors, fonts, the strip, the side tab, the chat) comes from /sites/packard.json in the kit repo. Change the kit or a config, deploy once, and every site picks it up within five minutes.