Hi !
Let me add my comment on this.
In my case, it just seems that when I try to play on the higher slot (after the one you show in the video), and I try exploring, in the end, a day after or the same day, I have my lips quite wrong… like swollen lip (not the chops) and then I have a bad/weird vibration that occurs at some note…
Maybe it’s because I didn’t had a proper warm-up.
Sometimes I just take the leadpipe to warm-up, get this free and easy feeling. But definitely, going one slot up seems that it makes me doing something wrong… and then makes my lips wrong… So I’d better stick on the 2 lower slot for now…