So I just watched your video, because honestly at this point I figured I'd humor you, and something felt really off, I could notice a delay after
every single GCD when using macros. It's really, really noticeable when watching it, I physically felt something was wrong (I have autism so this genuinely triggers that sort of reaction in me when I can tell something is off). I even had to mute the video and watch it without sound to make sure I wasn't imagining it due to the UI sounds.
I even logged into the game and tested my GCD to make sure I wasn't wrong and ground myself to something I can control.
My dude, you are definitely clipping on every single GCD, if you say you're not, I'm convinced you don't actually know what clipping is, or just haven't learned to feel small instances of clipping (similar to how some people can't tell the difference between 30fps and 60fps). But you are 100% clipping in your video. The GCD isn't smooth when it rolls over onto the next.
The video I watched, since you called someone else out for using the wrong video:
https://www.youtube.com/watch?v=H-LgAGXETgA