I actually don't want my Kagi plugin to overwrite Google for a different reason: Sometimes the plugin fails to hijack my search, and I really don't want my searches going to Google. So I overwrite DuckDuckGo, so even the fallback is okay.
And what's more. Where do the requests for autocomplete/suggestions get sent? Because the Kagi plugin works by redirecting the result page. So whilst typing the search question in the address bar of the browser requests are made to autocomplete/suggest the search question. These are still sent to Google (or whichever search engine selected).