Portland’s Planning Board heard from neighbors of the proposed Roux Institute on Tuesday after the developer scaled back its plans due to residents’ concerns about the size of the campus, the height of its buildings and the traffic it could generate. The Institute for Digital Engineering and Life Sciences, which is developing the future home of the Roux Institute, is asking for a zoning change to allow the institute to grow over time. Carol Schiller, who has lived in the neighborhood for 32 years, believes the project should move forward with no further reductions, because it will help Maine keep high technology talent in the state. “I urge you to go forward and support this groundbreaking gift to the state of Maine.