This looks and sounds awesome! Definitely your best result yet. I would also point out that you’re doing this for 40 seconds straight in this video, which is a test of fluidity in and of itself. If there’s something wrong with the motion, you will start to feel tension way before that. We get the “elbow feels tense” thing all the time, but great players do it and claim it feels very relaxed. If you’ve figured out a way to get it to feel easy then that’s a good start.
Also, elbow motion and wrist motion often occur together, probably because they can move in similar planes. Vinnie does lots of wrist stuff intermingled with his elbow motion and so does Bill Hall. We spent a lot of Bill’s interview talking about the interplay of these techniques. My guess is that choosing elbow as a default is just that — a starting point. Over time you learn to augment with other motions as the phrases require, and eventually they blend together to feel like “one” overall technique even though at the level of the motions there is mixing and matching.
You can check out the Brendon Small interview for his thoughts on what “easy” elbow motion feels like, and of course the Bill Hall interview as well where we talk a lot about it. In fact, if you feel you want a second look at this from someone who actually plays this way regularly, you could reach out to Bill for a consultation. I think he does teaching, not sure, but he’s a super nice dude so worth a shot.