@leocg Hi, I have been looking for something search engine related too, so let me weigh in here.
In Chrome, when you visit a search engine that is not yet listed as one of the available search engines in the browser, Chrome will add it to the list and you can even choose to use it as the default SE.
To be exact, I would like the SE https://Searx.me/ added, and I did add it manually, however it won't search anything from the address bar, it will just direct me to the home page. Maybe I did something wrong, but I can't find out what.
Anyway, adding the feature would not only solve my problem, but make it easier for everyone.