A young lady I know completed high school with an AA degree (dual enrollment) and completed her undergraduate degree at University of Miami in two years and immediately enrolled at UPenn Law School. She completed her law degree at age 23 and was hired by a very prestigious Law firm, making in excess of $150K/yr. The opportunity cost here is over $300K!
I don’t see any disadvantages with finishing your undergraduate degree in 3-years, while getting a jump start at paying down the expected large law school debt.