Hello, we're sorry that this addon does not suit you but here is a second addon, it does not change your homepage and only sets Qwant as your default search engine. https://addons.mozilla.org/fr/firefox/addon/qwant-com/

The fact that you cannot revert your homepage is truly an issue and we've already asked Mozilla if the override of the homepage could be consensual, but as of today, if an extension wants to set the user's homepage, there is no other way than what we did, this is why we do provide another addon.