I use Qwant as my default search engine because I thought it was more respectful of my privacy than Google or Bing and DuckDuckGo is not giving so good results in my country (for localization related searches).
I noticed that the engine was removed from the default engines for URL bar in latest IronFox version. So I searched a bit about why so, and found this issue in their tracker : https://gitlab.com/ironfox-oss/IronFox/-/issues/47.
What to think about this ? The message from ironfox dev seems clear but qwant seems to claim that the shared data are anonymized.
Did you read the link about privacy pass? I’m guessing not since you think that your searches are somehow tracked with that.