Have you ever thought of using iron on hinges. Granite state marketed them for years. It is just a two strips of supercoverite sewed together. Each strip spans the gap and the line of thread is the hinge point. They are gapless, limp, and hold on the entire trailing edge. I've used them in models from 1/2a to giant scale without a failure.
When Granite state hinges became hard to find I just made my own.