I think either of those are great. I also really don't think it matters if you labeled it as most meaningful or not and your worried about repeating yourself. If it was a MM experience and you think it also brings you diversity then that's great. I'll never understand why people on here tell you not to repeat your most meaningful experiences as something else. I'd rather my application be consistent, then spread myself thin because I want to seem more well-rounded. I'd say you can't lose with either of them.