I assume that if credits goes to EpickHack you're not the creator of this app, but anyway... If it's stated that it's permanent VACsafe it mustn't read/write game memory, so it just checks if CS GO window is active and then sets a trigger which puts the crosshair a few pixels lower each time left mouse button is being clicked or after each past amount of time left mouse button is being pressed. Am I right? If so, it's not effective to kill off recoil, because it's pattern has irregular shape and is different from plain vertical line.