In a study by a group of Harvard Kennedy School graduate students, developers highlighted permitting as a “critical constraint” in Belmont. “The cost essentially increases because the permitting is unpredictable,” grad student Josh Young told the Select Board earlier this month. On May 11, the student group presented to the town for the second time, this time to share its findings on the development feasibility of the Brighton Street Corridor. Previously, the students offered insight into the Belmont Center overlay,…