It's remotely possible that, turning that switch  ON  might possibly allow you to use Download Mode IF you can supply the Code for it.  Having Download Mode isn't critical once you haver TWRP but, still a smooth option .  As far as Destiny is concerned, I'm betting that, if ya write a variant for 2.8.7  for an LG Leon, you should be in . Somebody gave me a Lucky and, tried putting your  U2  version 2  on it and, quickly ganked that Lucky !  It even deauthorized the ADB bridge. No **** !  Tried an AOKP Boot Animation and well, you know the rest .  These fones are an amazing challenge !