I use Kagi (along with DuckDuckGo) and I really appreciate the quality of their search results, but if you care about privacy do not use their Safari extension.
In addition to this, since all the search attempts are being redirected to Kagi, you can’t use any other search engine unless you deactivate the extension and this prevents you from trying the same query on different engines.
P.S: as far as I understand, they don’t have much freedom with the implementation and everything would be much easier if Safari allowed to customise the search engines, but I’m not sure this limitation is being properly communicated to the users (unless I missed some warning during extension installation)
Due to a Safari limitation, all the queries are leaked to the previously selected default search engine https://kagifeedback.org/d/1575-ios-extension-leaking-search...
In addition to this, since all the search attempts are being redirected to Kagi, you can’t use any other search engine unless you deactivate the extension and this prevents you from trying the same query on different engines.
P.S: as far as I understand, they don’t have much freedom with the implementation and everything would be much easier if Safari allowed to customise the search engines, but I’m not sure this limitation is being properly communicated to the users (unless I missed some warning during extension installation)