First of all, I should say that your work on the audio and music enhancements is absolutely fantastic and seamlessly integrated. However, I’m not sure how I feel about the “modernisation” of the first two films. Films from the '90s and early 2000s had a certain look and aesthetic that made them unique. With the limitations of the era’s technology, filmmakers had to find clever and creative ways to make things work. You’re right that we never got to see McGonagall’s transformation, but that shot of her shadow on the wall changing shape is pure perfection. It’s been engraved in my mind since childhood as one of the most iconic moments of the series.
That being said, I also found the other additions of yours, like the back shot of Dumbledore and McGonagall walking, to be a nice touch. Same with Hagrid riding through the clouds, although I would suggest moving those shots earlier, before the professors notice him in the sky, because it looks like he’s flying far above the land.