My experience with PLTW is fairly specific to a vocational high school setting, within an engineering curriculum. The feedback I have heard from faculty and students generally has been quite positive. I don't know exactly how it would work with a child with this particular profile, but I do know that we have had a couple of extremely bright students experience success in it. In our building, all students have the option to do internships (co-ops) in late 11th and all of 12th grades, and the health/medical/dental shops all do closely supervised externships beginning in 11th grade. I have yet to see a difficulty with any student being too young. In most states, you can get a work permit at age 15. When on internship, work hours count as instructional time, which I think moderates the typical hours/wk limits placed on young members of the workforce.
I'm assuming you've already looked at their website:
https://www.pltw.org/our-programs/pltw-biomedical-science
