This is my opinion about the Growth feature, I've just checked contribution of the last user that asked a question. I've seen that he has some newcomers tasks done, (added wiki links to some pages). And I've seen that often metees ask how long it will take for their edit to be approved (on Polish Wikipedia edits need to be approved to be visible).
The problem I see is that there are not much connection between mentor and mentees. When I sign up for being a mentor (in Polish Wikipedia) they said that I will answer questions maybe once or twice a week. There is MentorDashboard but I don't think that is really useful. I don't check it that often.
But if there was a page that list all my mentees recent edits that, maybe with some filters not sure what they should be, it would be much better if mentor can look at new edits and approve them faster. Maybe it would be even better of the edits are inline with button to approve, so it will be fast and easy for mentor to just check and approve the edits and hide edits that he checked.
Also one more feature that this page should have is thank you link on each edit.
And all this because if someone add his first edit and get it approved and visible faster, and mentor will give him personal thanks. It will increase the number of people that will keep using Wikipedia as editors. It would probably also be good idea to send notification when newcomer edit is approved, this will "force" them to open Wikipedia and see his/her edits. Those can be Preferences set by default, even on Wikipedia that don't require approval for a change to be visible (like in English Wikipedia). Notification for the newcomers that his or her edits was approved, would probably be boost of dopamine for the newcomers and he or she would like to edit more.
Another idea is that it would probably be fun to add some Gamification to newcomers, not sure how. Gamification is the topic that I'm interested and need to give more focus in 2022.