Generally you need good academics to get in good dual programs and they may have moderate to high time demands.
However, it all depends upon which BS-MD programs you are aiming at, which race/income/geography group you are from, what are your work habits etc. Some can juggle academics with lots of extracurricular s, others can’t handle academic rigor even if it’s their single focus.
For example in Texas, admission and workload at Texas Tech’s dual program may accommodate you but Rice-Baylor type dual program would demand academic excellence for both admission and survival there.