It looks great!
I think it can be improved, if you use layers for the dialogues, by making the dialogue globes appear on a fade as the video progresses or make some emphasis on them like you did with the ones you zoomed in to; at times I missed some dialogues, but then again, I've never used IMovie nor Procreate (I've only used Movie maker, lol) and don't know which limitations have for that.
I more or less made a trailer for Chapter 5 before redrawing/fixing parts of my comic:
https://www.instagram.com/p/CG_92iIj6nY/
I shared it as an IG story too back in halloween with the first 15 seconds of Green Day - When I Come around, but I think I'd go on trouble if doing the same on youtube.
