[whatsthatabout]

Depends on how the extension works probably. Had the issue with some extension but the Qwant extension for example doesn't leak - you can check yourself when capturing the http(s) traffic with something like proxyman.

[lapcat]

All the Safari search engine extensions work the same: https://lapcatsoftware.com/articles/2025/2/2.html

[whatsthatabout]

Interesting, something must have changed then - the qwant search extension definitely does not leak the search to the default search engine - I checked myself with Proxyman.