RE: biomedical science --I looked at some of the course requirements at different schools. I would say it depends on what college you’re attending. There doesn’t appear to be a great of consistency from one school to the next about what exactly is a biomedical science major. At one program, biomed science was the de facto pre-vet major. At most others, it’s clinical lab science --which is a vocational degree designed for individuals who want to be hospital/clinical lab techs or pathology assistants. Neither of those are ideal pathways for a pre-med. If the college you plan to attend offers a BMS degree that doesn’t fall into either of the above categories, then it might be a viable major for a pre-med.
And I’m not IWBB, but D1 & D2 both dedicated about 2 months to MCAT prep. (Both were on gap years and both were working more than full time while also doing MCAT prep.)