3 notes per string

In this video: 1. I perform a 3 note per string "riff", but its just open strings, so no left hand action. This is so that my speed is not inhibited by my left hand. I'm not sure whether I'm doing a proper RDT DBX or stringhopping. If I am stringhopping, which would make sense because I can't get much faster than this, I have no idea how to stop and transition to RDT DBX. 2. I do a simple tremolo on a single open string. This looks to me like a DSX with wrist motion. 3. I do (1) again but attempt to do it faster, but fail because (1) was roughly my max clean speed.