I have an endless controller setup for manually scratching the video. When it reaches the end going forward it loops seamlessly around, even when jogged by my controller. Trying to pull a movie backwards though, while it is playing forwards, it will not loop around the beginning to the end. It won't loop backwards via midi scratching if the play direction is forward, or vice versa. It only loops in the direction of play, so you can't scratch it backwards with a midi controller
When a animated parameter or transport is on a continuous loop the direction doesn't matter to Resolume but it is an unnecessary restriction for controllers.