Welcome, I don't know if the Umbraco team already discussed the subject of assigning an issue for such user to work on it and let the others know that someone is working on it. I already meet this in Gitlab Hackathon before and when you want to work on the issue you ask the team to assign it to you, I know the repo on Gitlab has permissions but possible to mention on the Contribution guide line to post a comment on the Github CMS issue that you are working on it as an alert for others.