The main purpose of the SBIR/STTR Application Assistance Act is to enhance support for small businesses applying to the Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) programs. These programs are designed to encourage small businesses to engage in federal research and development, and this legislation aims to broaden participation, particularly from underrepresented groups and institutions. Key provisions of the Act include extending the existing FAST program, which provides assistance to small businesses, until September 30, 2030.