Most trainers, though really useful, lack the invincible option: Deathsmiles, Deathsmiles IIX, the Dodonpachi series, Mushihime sama, Eschatos, Ginga Force, Raiden IV, Raiden fighter jets,the Shooting Love compilations and Espgaluda2, whose trainer (available here) is not fully functional.
Is there any reason why this hasn't been done before and could it be looked into? Shmups seem popular enough to be included in the 190+ games trainer, that's also why I'm asking.