I actually can only speak from the perspective of someone who will be a part of Tri-I this fall. The program is amazing from those I've met who participated, and you get to work closely with MD-PhD students in the summer. Living in the UES is a plus, and having a connection at Tri-I before applying can really set you apart.
It should also be noted that Dr. Andersen regularly tries to bring together directors of other top MSTPs. With it, he advertises Gateways... so I would venture to say they are familiar with the program.
It can only help you.