I took a close look at the proposed runway and the terrain around the airport. It's a operational nightmare for airline ops with larger aircraft. I am not completely sure it's even feasible. ILS approaches require 6 miles of straight away. Not possible at EIS. A GPS approach could be used however generally you want a 3 mile straight segment. That can be reduced to 1.5 miles but that still puts large jets turning final over fat hogs bay. With a short final the airport will be classed as special and require additional crew training and currency obligations upping costs.
For less then 10 cents on the dollar the BVI could set up a modern ferry system and set up reliable large turboprop service to connect in SJU. Maybe common sense will prevail.
G