Things in medical school admissions change very rapidly every year, becoming more and more competitive each year (10-15% more applicants this year?). My older daughter who didn’t feel any pressure when she applied in 2015 and did extremely well with getting interviewed, was telling us recently she is not sure how well she would do now. This is based on advising students who are applying and getting paid 10 times her hourly salary as a resident for that advice (residency is a minimum wage job).
If I was a medical school admissions person, the first thing i would wonder about is whether this person is suitable for the profession since it would look like gaming the system just for GPA (that is the only conclusion one can draw if someone spent all summers taking premed classes outside their own school). I can imagine a full schedule at their school preventing them from taking every course and having to do some summers outside but an entire premed courselist sounds very unrealistic. I do know several med students who have taken some summer classes in community colleges while they are home but not more than 2-3 classes that are premed focused. Many state school students take required classes in history (Texas schools require texas state history) or english or something else for their graduation in Texas so they can actually take premed classes during school year. If someone finished undergrad, decided they now want to apply for medical school and so went back and did all their classes somewhere (ANYWHERE), it does not have the same question mark. They are now a nontrad.
Not all schools have committee letters. If a school has a committee letter and one does not get one, then it is a question mark. However, if one takes a gap year, they can use that to support not having a committee letter.