[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.

[lapcat]

I just tested with Little Snitch and saw leakage to Google.

It's a race condition, so you might not always see it.

[whatsthatabout]

I don't know your setup but in my opinion something like proxyman / mitmproxy or even Wireshark would be the better way to analyse this. I tested quite often and never saw the leak with Qwant.