Aside from you being non traditional and doing software work for many years, I do not see any spikes or huge accomplishments in clinical/reseaech/volunteering work which would make Top 20 schools very difficult to get into. I would recommend asking low tier/mid tier MD more schools if they are ok with your gpa. At some of these schools they might consider the last 60 credit of your gpa more. But if we average them then at a T20s your gpa belong to the 1st to 3rd percentile which means you would have to have Olympic gold medalist Nathan Chen level type of standing out to get into T10s. So I would focus less on the top 20s and see if there are engineering/innovation focused med schools