Developer Building and Land Technology announced Tuesday that it would explore new projects for the 14-acre peninsula that it owns in the city’s South End, a site that was controversially proposed several years ago as a headquarters for the world’s largest hedge fund. As the developer of the mixed-use Harbor Point complex that encompasses 100 acres across the South End, BLT is proposing as much as 1 million square feet of new buildings on the waterfront property. But controversy has long overshadowed the land. BLT angered many residents and local officials when it tore down the peninsula’s boatyard in 2011, when it ended its lease with Brewer’s Yacht Haven West. Today, BLT and other key backers appear undeterred by the contention of the past decade. BLT’s press release for the project included laudatory statements from Gov. Ned Lamont and Stamford Mayor David Martin.