Would love to see that After Effects file one day. Scroll animations always fascinate me. Did you work closely with your web developer for the scroll functions or did you set that up in the AE file?
The AE file is a bit complex of course but also quite straight forward We have scaled off all extetions and aplha channels stuff and just goning for classic animations , positions, scale, opacity etc. Timing is important.
for the scroll we use GSAP and that works nice. Thay have som good exampels to get you going.